Joules to kWh Formula

The conversion from joules to kilowatt-hours is exact because it comes directly from the definitions of watt, kilowatt, second, and hour. One watt is one joule per second. One kilowatt is 1000 watts. One hour is 3600 seconds. Therefore, one kilowatt-hour is 1000 joules per second sustained for 3600 seconds.

For example, \(7{,}200{,}000\text{ J}\) converts to \(2\text{ kWh}\), because \(7{,}200{,}000\div3{,}600{,}000=2\). The energy amount does not change; only the unit changes. Joules are the SI unit of energy, while kWh is a practical larger unit for electrical energy.

What Joules and kWh Mean

A joule is the SI unit of energy. It appears in physics, mechanics, heat transfer, electrical work, chemical energy, and many engineering equations. A joule is small on the scale of household electricity. That is why everyday electrical energy values often become millions or billions of joules.

A kilowatt-hour is a practical unit of energy equal to one kilowatt used for one hour. Utility bills use kWh because household and commercial electrical consumption is easier to read in kWh than in joules. A home using 500 kWh in a month has used \(1{,}800{,}000{,}000\text{ J}\), but the kWh value is much easier for billing and comparison.

The two units describe the same kind of quantity: energy. Joules are preferred in SI equations, lab calculations, heat, work, and mechanics. kWh is preferred for electricity bills, battery capacity, appliance usage, solar production, and energy cost estimates. This page starts with joules and converts to kWh. For the reverse direction, use the dedicated kWh to joules conversion page.

How to Convert Joules to kWh Step by Step

1. Write the energy value in joules.
2. Divide the joule value by \(3{,}600{,}000\).
3. Label the result in kWh.
4. Check by multiplying the kWh result by \(3{,}600{,}000\) to recover the original joules.

For example, \(18{,}000{,}000\text{ J}=18\text{ MJ}\). Divide 18 by 3.6 and the answer is \(5\text{ kWh}\). This megajoule shortcut is often easier than working with all the zeros in the raw joule value.

Quick Reference Table

The table below gives common joule-to-kWh conversions. It includes small physics-scale values, appliance-scale values, and larger energy blocks so you can see how quickly joule values become small kWh decimals or practical kWh totals.

If a joule value is large, kWh can make it easier to compare with real electrical energy usage. If the value is small, joules, kJ, or Wh may be clearer than a long kWh decimal.

Worked Examples

Using Joules to kWh for Electricity Bills

Electricity bills normally use kWh because energy companies bill by kilowatt-hour. If a physics, engineering, or monitoring system gives energy in joules, converting to kWh makes it possible to estimate cost. The cost formula is simple once the energy is in kWh.

Suppose an energy monitor reports \(18{,}000{,}000\text{ J}\). The kWh value is \(18{,}000{,}000\div3{,}600{,}000=5\text{ kWh}\). If electricity costs 0.15 per kWh, the estimated cost is \(5\times0.15=0.75\). The calculator includes an optional price field for this reason.

Cost estimates should use the billing unit specified by the utility. Tariffs may include fixed charges, tiered rates, time-of-use pricing, taxes, demand charges, fuel adjustments, or other fees. The joules-to-kWh conversion gives the energy portion, but a full bill may need more than a simple multiplication.

Energy, Power, and Time

The relationship between joules and kWh becomes clearer when energy, power, and time are separated. Energy is the total amount transferred or used. Power is the rate of energy transfer. Time is the duration. In SI units, the relationship is:

In electrical billing form, the same idea is written as:

A 1000 W appliance running for one hour uses \(1000\text{ W}\times3600\text{ s}=3{,}600{,}000\text{ J}\), which is 1 kWh. A 500 W appliance running for two hours also uses 1 kWh. The kWh unit packages power and time into a practical energy amount.

If you need to move between watts and kilowatts before calculating energy, use watts to kW conversion or kW to watts conversion. For broader power-unit work, the power conversion page is the better hub.

Joules, kJ, MJ, GJ, Wh, and kWh

Energy can be written using several related units. Joules are the SI base energy unit. Kilojoules, megajoules, and gigajoules are SI-prefix forms. Watt-hours and kilowatt-hours connect energy to electrical power over time. The same energy can be written in any of these units, but the most readable unit depends on scale and audience.

If your target is kJ rather than kWh, use the joules to kJ conversion page. If your starting unit is kJ and you need joules, use kJ to joules conversion. Those pages answer different conversion intents from this joules-to-kWh page.

Scientific Notation for Joules to kWh

Scientific notation is useful because joule values can contain many zeros. The conversion factor \(3{,}600{,}000\) can be written as \(3.6\times10^6\). This makes large conversions easier to inspect.

If \(E=4.5\times10^7\text{ J}\), then:

If \(E=9.0\times10^5\text{ J}\), then:

The exponent comparison helps catch scale mistakes. A value near \(10^6\text{ J}\) should be a fraction of a kWh to a few kWh. A value near \(10^9\text{ J}\) should be hundreds of kWh.

Battery and Solar Energy Context

Batteries and solar systems often use kWh because kWh is practical for stored or generated electrical energy. A battery might store 13.5 kWh. A solar array might produce 18 kWh in a day. A physics calculation or simulation, however, may output joules. Converting joules to kWh lets you compare that output with familiar electrical system ratings.

For example, a simulation might report \(48{,}600{,}000\text{ J}\) of stored electrical energy. Dividing by \(3{,}600{,}000\) gives \(13.5\text{ kWh}\). That is easier to compare with a battery specification. A solar production value of \(64{,}800{,}000\text{ J}\) converts to \(18\text{ kWh}\), which is easier to compare with daily household energy use.

If you are estimating solar output before conversion, use the solar panel calculator. Once you have energy in joules, this page converts it into kWh for electricity-style comparison.

Physics Problems That End in Joules

Many physics formulas naturally produce joules when SI units are used. Kinetic energy, gravitational potential energy, electrical work, heat, and mechanical work can all be expressed in joules. Sometimes the next step is to compare that result with an electrical energy value, an appliance load, a battery capacity, or a utility bill. That is where joules to kWh conversion becomes useful.

For example, if a kinetic energy calculation gives \(10{,}800{,}000\text{ J}\), the kWh value is \(10{,}800{,}000\div3{,}600{,}000=3\text{ kWh}\). If a potential energy calculation gives \(1{,}800{,}000\text{ J}\), the kWh value is \(0.5\text{ kWh}\). Use the kinetic energy calculator or potential energy calculator for those source energy calculations.

Heat, Thermodynamics, and Efficiency

Heat calculations often use joules because heat is energy. A common heat equation is \(Q=mc\Delta T\). If a thermal calculation gives \(Q\) in joules and you want to compare that heat with electrical energy consumption, convert joules to kWh.

Suppose a heater transfers \(9{,}720{,}000\text{ J}\) of useful heat. The equivalent electrical energy is \(9{,}720{,}000\div3{,}600{,}000=2.7\text{ kWh}\). If the heater's electrical input was 3 kWh, the useful heat output is 2.7 kWh equivalent, giving an efficiency of \(2.7/3=0.90\), or 90%.

Always convert both energies to the same unit before calculating efficiency. Dividing joules directly by kWh produces a mixed-unit result unless one value is converted first.

Energy Unit Comparisons

Joules are not the only energy unit. Different fields use different units: BTU for heating and cooling, calories and kilocalories for food and nutrition, electronvolts for atomic and particle physics, and kWh for electrical energy. Converting through joules can help compare these systems.

If you need BTU, use joules to BTU conversion or BTU to joules conversion. If you need food-energy units, use joules to calories conversion, joules to kcal conversion, calories to joules conversion, or kcal to joules conversion. If your work involves electronvolts, use joules to eV conversion or eV to joules conversion.

Those pages should not compete with this one. This page answers the specific question: "How do I convert joules to kWh?" The related pages answer different starting-unit and target-unit needs.

Reverse Conversion: kWh to Joules

The reverse conversion multiplies kWh by \(3{,}600{,}000\). This page includes a reverse check in the calculator output, but the full reverse topic belongs on the dedicated kWh to joules conversion page.

For example, \(4\text{ kWh}\times3{,}600{,}000=14{,}400{,}000\text{ J}\). The reverse direction is useful when an electricity bill, appliance rating, or battery specification is in kWh but a physics equation requires joules.

Common Mistakes When Converting Joules to kWh

The most important benchmark is \(3{,}600{,}000\text{ J}=1\text{ kWh}\). Any answer should scale from that fact. If \(3{,}600{,}000\text{ J}\) does not produce 1 kWh in your calculation, the conversion factor or direction is wrong.

Reporting, Rounding, and Significant Figures

The conversion factor is exact, so rounding usually comes from the source energy value. If a value is measured as \(7.20\times10^6\text{ J}\), the result should usually preserve three significant figures: \(2.00\text{ kWh}\). If a value is rounded to \(7{,}000{,}000\text{ J}\), reporting a long decimal kWh value may imply more precision than the source supports.

For electricity-bill comparisons, kWh values are often reported to one, two, or three decimal places depending on the utility or monitoring system. For physics homework, significant figures may be more important than fixed decimal places. For spreadsheets, it may be best to keep full precision in calculation cells and round only the displayed output.

Scientific notation can also clarify precision. \(3.60\times10^6\text{ J}\) converts to \(1.00\text{ kWh}\), preserving three significant figures. Writing 1 kWh is numerically correct, but it may not show the precision intended by the source data.

Spreadsheet Formula for Joules to kWh

If a spreadsheet cell contains energy in joules, the formula is direct. If cell A2 contains joules, use:

In spreadsheet syntax, this is usually =A2/3600000. If A2 contains 7200000, the output is 2. Label the output column as kWh so the unit is not lost. If you also estimate cost, multiply the kWh column by the price-per-kWh column.

A good spreadsheet audit check is to multiply the kWh output by \(3{,}600{,}000\) in a separate check column. The result should match the original joule value, allowing for display rounding. If it is off by a factor of 1000, you may have converted to Wh or MWh by mistake.

Choosing the Right Energy Tool

Use this calculator when the source value is in joules and the target is kilowatt-hours. Use the reverse kWh to joules conversion page when the source value is kWh. Use energy conversion or the advanced energy conversion tool when you need several energy units at once.

If you are working with heating and cooling units, use BTU to kWh conversion or kWh to BTU conversion. If you are working with power rate before energy, the easy power converter can help. Keeping each tool focused lets each page rank for its own conversion intent without competing with this joules-to-kWh page.

Manual Conversion Methods

The most reliable manual method is to divide by \(3{,}600{,}000\). If the number is large, first convert joules to megajoules by dividing by \(1{,}000{,}000\), then divide the MJ value by 3.6. This two-step method is often easier to do mentally.

For example, \(54{,}000{,}000\text{ J}=54\text{ MJ}\). Then \(54\div3.6=15\text{ kWh}\). Another example: \(900{,}000\text{ J}=0.9\text{ MJ}\). Then \(0.9\div3.6=0.25\text{ kWh}\).

A second method is to convert joules to Wh first. Since \(1\text{ Wh}=3600\text{ J}\), divide joules by 3600 to get Wh. Then divide Wh by 1000 to get kWh. The combined factor is \(3600\times1000=3{,}600{,}000\), which matches the direct formula.

Appliance Energy Examples

Appliance energy is often easier to understand after joules have been converted to kWh. A raw joule number can look very large, but the kWh value usually maps better to familiar electricity use. For example, \(1{,}800{,}000\text{ J}\) is only \(0.5\text{ kWh}\). A small heater, kettle, oven, dryer, air conditioner, or washing machine may use that scale of energy in a short session, depending on power rating and run time.

Suppose an appliance monitor reports \(10{,}800{,}000\text{ J}\) for one cycle. Divide by \(3{,}600{,}000\) and the cycle uses \(3\text{ kWh}\). If electricity costs 0.20 per kWh, the estimated energy cost is \(3\times0.20=0.60\). If the same cycle runs 20 times per month, the monthly energy is \(60\text{ kWh}\), and the estimated energy cost is \(60\times0.20=12.00\). The conversion turns a scientific energy value into a household energy comparison.

For smaller devices, Wh may be more readable than kWh. A laptop charge might be better described as 60 Wh than 0.06 kWh. In joules, that same energy is \(60\times3600=216{,}000\text{ J}\). All three values are equivalent, but each unit fits a different scale. Joules are useful in physics. Wh is useful for small electronics. kWh is useful for utility-scale comparisons.

When comparing appliances, do not confuse power rating with total energy. A 1500 W appliance does not automatically use 1.5 kWh. It uses 1.5 kWh only if it runs for one hour. If it runs for 20 minutes, the energy is \(1.5\times\frac{20}{60}=0.5\text{ kWh}\), which is \(1{,}800{,}000\text{ J}\).

Battery Capacity and Stored Energy

Batteries may be described in Wh, kWh, joules, amp-hours, or watt-hours depending on the product and context. Large batteries are usually easier to compare in kWh. Small batteries may be easier to compare in Wh. Physics and engineering calculations may produce joules. Converting joules to kWh helps connect those contexts.

If a battery stores \(48{,}600{,}000\text{ J}\), the kWh value is \(48{,}600{,}000\div3{,}600{,}000=13.5\text{ kWh}\). This is a practical battery-storage number. If a smaller battery stores \(180{,}000\text{ J}\), the kWh value is \(0.05\text{ kWh}\), and the Wh value is 50 Wh. The Wh output is clearer for a small pack, while the kWh output is still useful for comparing with household energy.

Battery capacity is not the same as usable energy under every condition. Discharge limits, inverter efficiency, temperature, battery age, and manufacturer reserve capacity can reduce usable energy. A joules-to-kWh conversion tells you the theoretical equivalent energy unit, not the full practical runtime of a device. For runtime, you also need load power and efficiency.

The basic runtime estimate is:

For example, a \(2\text{ kWh}\) usable battery powering a \(0.5\text{ kW}\) load has an ideal runtime of \(2/0.5=4\text{ hours}\). Real-world runtime may be lower because of conversion losses, standby load, and battery management limits.

Solar Production and Energy Monitoring

Solar systems often report daily and monthly production in kWh because kWh matches electricity billing and household consumption. However, simulations, sensors, or physics calculations may output joules. Converting joules to kWh makes solar production easier to compare with appliance use and grid consumption.

Suppose a solar model estimates \(64{,}800{,}000\text{ J}\) for one day. The kWh value is \(64{,}800{,}000\div3{,}600{,}000=18\text{ kWh}\). If the same average output occurs for 30 days, the monthly energy is \(540\text{ kWh}\). That value can be compared directly with a monthly electricity bill, battery capacity, or self-consumption target.

Solar energy estimates should be interpreted with care. Panel rating, sunlight hours, shading, orientation, inverter losses, temperature, dust, wiring losses, and battery charging efficiency all affect actual energy delivered. The conversion from joules to kWh is exact, but the source estimate may still contain assumptions. Use kWh as the reporting unit after the estimate is calculated, not as a guarantee of real production.

When combining solar, battery, and appliance data, keep all energy values in one unit for comparison. If a solar model gives joules, a battery sheet gives kWh, and an appliance monitor gives Wh, convert all values to kWh or Wh before adding, subtracting, or comparing. The arithmetic is easier to review when the units are consistent.

Mechanical Work Compared With Electrical Energy

Mechanical work calculations commonly produce joules. If you want to compare mechanical work with electricity use, converting joules to kWh gives a practical bridge. The mechanical work formula \(W=Fd\) gives joules when force is in newtons and distance is in meters. A large mechanical-work value may still be a modest amount of electrical energy when expressed in kWh.

For example, lifting a heavy object may require \(360{,}000\text{ J}\). In kWh, that is \(360{,}000\div3{,}600{,}000=0.1\text{ kWh}\). If a motor and drivetrain are 80% efficient, the electrical input would be higher than the mechanical work output. The ideal 0.1 kWh output would require \(0.1/0.80=0.125\text{ kWh}\) of electrical input.

This kind of comparison is useful for motors, pumps, elevators, electric vehicles, and industrial equipment. The joule value comes from mechanics. The kWh value connects the result to electrical supply, battery draw, and energy cost. Always keep efficiency as a separate factor so the conversion itself remains clear.

When to Keep Joules and When to Use kWh

Joules are best when the calculation is based on SI physics equations. Kinetic energy, potential energy, mechanical work, heat transfer, electrical work, and many engineering formulas naturally use joules. If you are solving an equation using kilograms, meters, seconds, watts, newtons, or volts and coulombs, joules usually fit the unit system cleanly.

kWh is best when the calculation is about electrical consumption, energy billing, appliance use, battery storage, solar production, or grid-scale comparison. A value such as 2 kWh is much easier to understand on a utility bill than \(7{,}200{,}000\text{ J}\). A monthly home energy value such as 600 kWh is much clearer than \(2.16\times10^9\text{ J}\) for everyday readers.

In polished explanations, both units can be helpful. A technical note might say: "The simulation produced \(45{,}000{,}000\text{ J}\), equivalent to \(12.5\text{ kWh}\)." This keeps the SI value for traceability and the kWh value for practical interpretation. The calculator provides multiple outputs so you can choose the format that fits your audience.

If you must use one unit throughout a report, choose based on the purpose. Use joules for physics derivations and kWh for electricity-cost discussion. Mixing units without labels is the real problem. Converting clearly and labeling every value avoids confusion.

Troubleshooting Unexpected Results

If a joules-to-kWh result looks wrong, start with the benchmark \(3{,}600{,}000\text{ J}=1\text{ kWh}\). A value smaller than 3.6 million J must be less than 1 kWh. A value larger than 3.6 million J must be greater than 1 kWh. This simple check catches many mistakes.

A result that is 1000 times too large often means joules were divided by 3600 instead of \(3{,}600{,}000\). Dividing by 3600 gives watt-hours, not kilowatt-hours. For example, \(3{,}600{,}000\div3600=1000\text{ Wh}\), which is \(1\text{ kWh}\). If you label 1000 as kWh, the answer is too large by a factor of 1000.

A result that is extremely large may also come from multiplying by \(3{,}600{,}000\) instead of dividing. Multiplication is the reverse direction from kWh to joules. If you start with joules, divide. If you start with kWh, multiply. The direction is the most common source of conversion errors.

If the input is written in kJ, MJ, or GJ rather than J, convert it to joules first or use the matching shortcut. For example, \(18\text{ MJ}=18{,}000{,}000\text{ J}=5\text{ kWh}\). If 18 is entered as joules instead of megajoules, the result will be \(0.000005\text{ kWh}\), which is not the intended value.

Data Logging, Sensors, and Software Outputs

Energy data from sensors, simulations, and software tools may appear in joules because joules are the SI unit. A building-energy model, physics simulation, power integration script, or embedded device may sum energy as joules internally. When the results need to be compared with bills, batteries, or solar generation, kWh is usually the better display unit.

If a data logger records power over time, energy may be calculated by summing power multiplied by time intervals. When power is in watts and time is in seconds, the sum is in joules. To report kWh, divide the final joule total by \(3{,}600{,}000\). Do not divide each tiny interval and then round aggressively, because repeated rounding can introduce unnecessary error.

If \(P_i\) is in watts and \(\Delta t_i\) is in seconds, \(E_{\text{total}}\) is in joules. Convert the final total to kWh after summing. This method is common in metering, telemetry, and engineering analysis because it keeps the raw calculation in SI units and the final report in a practical energy unit.

For software files, store the unit explicitly. A column named "energy" is ambiguous. A column named "energy_j" or "energy_kwh" is much safer. If both columns are included, the relationship should be consistent: \(energy\_kwh=energy\_j/3600000\).

Energy Accounting Checklist

Before using a converted kWh value in a report, worksheet, or cost estimate, check the source and calculation context. The conversion factor is straightforward, but the surrounding assumptions can matter.

• Confirm the source unit. Make sure the input is joules, not kJ, MJ, GJ, Wh, or kWh.
• Use the correct direction. Joules to kWh divides by \(3{,}600{,}000\). kWh to joules multiplies by \(3{,}600{,}000\).
• Keep power separate from energy. Watts and kilowatts need a time duration before they become energy.
• Round at the end. Keep sufficient precision during calculations, then round the displayed result for the audience.
• Use consistent units for comparison. Convert all values to kWh, Wh, or joules before adding or comparing them.
• State assumptions for cost. Price per kWh may not include fixed fees, taxes, demand charges, or time-of-use differences.

This checklist is useful for students, homeowners, engineers, and analysts. Most errors are not caused by difficult mathematics. They come from using the wrong source unit, applying the reverse factor, comparing mixed units, or forgetting that power and energy are different quantities.

Additional Example Scenarios

Electricity Cost Estimates and Their Limits

The optional cost output in the calculator is useful for a quick estimate, but it should be interpreted as an energy-only estimate. The basic calculation is \( \text{kWh}\times\text{price per kWh} \). This works well when you want a simple comparison, such as estimating the cost of one appliance cycle, one battery charge, or one measured energy event. It is not a complete replacement for a detailed utility bill calculation.

Many electricity bills include more than one charge. There may be a fixed monthly service fee, taxes, fuel adjustments, delivery charges, time-of-use rates, demand charges, minimum charges, or tiered pricing. If a home or business uses time-of-use pricing, the same kWh value can cost different amounts depending on when the energy is used. A joules-to-kWh conversion gives the energy amount, but the tariff structure determines the final bill.

For example, \(36{,}000{,}000\text{ J}\) converts to \(10\text{ kWh}\). At 0.12 per kWh, the simple energy cost is 1.20. At 0.30 per kWh, the same energy costs 3.00. If half of the energy is used at an off-peak rate and half at an on-peak rate, the estimate needs two separate multiplications. The energy conversion stays the same, but the pricing calculation becomes more detailed.

When reporting cost, keep the original kWh and the price assumption visible. A clear note is: "\(18{,}000{,}000\text{ J}=5\text{ kWh}\). At 0.15 per kWh, estimated energy cost is 0.75." This makes the conversion, rate, and cost calculation easy to review. If the price is only an assumption, state that it is an estimate and not an official bill.

Unit Interpretation in Mixed Energy Problems

Many real problems combine values from different sources. A physics calculation may give joules, an appliance label may give watts, a battery specification may give Wh, and an electricity bill may give kWh. Before comparing these values, convert them to a common energy unit. The best common unit depends on the purpose: joules for SI equations, Wh for small electrical devices, and kWh for household or grid energy.

Consider a problem that gives a motor's useful mechanical work as \(1{,}080{,}000\text{ J}\), an input energy as 0.4 kWh, and a battery capacity as 500 Wh. Convert everything to one unit before interpreting. The useful work is \(1{,}080{,}000\div3{,}600{,}000=0.3\text{ kWh}\). The battery capacity is \(500\text{ Wh}=0.5\text{ kWh}\). Now the values are easy to compare: useful output is 0.3 kWh, input is 0.4 kWh, and the battery stores 0.5 kWh.

This kind of unit alignment prevents hidden errors. If someone divided 0.4 kWh directly into joules without conversion, the result would have no clear meaning. If someone treated 500 Wh as 500 kWh, the battery would appear 1000 times larger than it is. Unit labels are not decorations; they are part of the calculation.

A good workflow is to make a small conversion table before solving the main question. List every source value, its original unit, the converted unit, and any assumptions. This is especially useful in project work, energy audits, lab reports, and engineering notes. A few lines of unit preparation often prevent much larger mistakes later.

Why Joules to kWh Uses a Larger Denominator Than Joules to Wh

A common source of confusion is the difference between watt-hours and kilowatt-hours. A watt-hour is \(3600\text{ J}\) because one watt is one joule per second and one hour is 3600 seconds. A kilowatt-hour is 1000 watt-hours, so it is 1000 times larger. That is why joules to kWh divides by \(3{,}600{,}000\), not by 3600.

If you divide \(3{,}600{,}000\text{ J}\) by 3600, you get 1000 Wh. That is correct, but it is not the final kWh value. You must divide by 1000 again to get 1 kWh. The two-step path is useful for learning, but the direct path is faster for repeated calculations.

This distinction also explains why a small device may be reported in Wh while a utility bill is reported in kWh. A 50 Wh battery is \(180{,}000\text{ J}\), or \(0.05\text{ kWh}\). The kWh value is correct, but Wh is easier to read for that scale. A 500 kWh monthly bill is \(1{,}800{,}000{,}000\text{ J}\), and kWh is much easier to read for that scale.

Final Check Before Reporting

Before reporting a joules-to-kWh answer, compare it with the benchmark \(3.6\text{ MJ}=1\text{ kWh}\). If your joule value is around \(3.6\times10^6\), the kWh answer should be around 1. If your joule value is around \(3.6\times10^9\), the answer should be around 1000 kWh. This quick scale check is often enough to catch a missing factor of 1000, a misplaced decimal point, or an accidental Wh result labeled as kWh.

Also check whether the final unit fits the audience. A physics solution may need joules as the final SI answer, with kWh only as an interpretation. A billing estimate may need kWh as the primary answer, with joules retained only for traceability. A good final answer includes the converted number, the unit, and enough context for the reader to know why kWh is being used.

Practice Problems

Try these manually, then use the calculator to check. Each answer uses \(\text{kWh}=\text{J}\div3{,}600{,}000\).

1. Convert \(3{,}600{,}000\text{ J}\) to kWh.
2. Convert \(7{,}200{,}000\text{ J}\) to kWh.
3. Convert \(900{,}000\text{ J}\) to kWh.
4. Convert \(36{,}000{,}000\text{ J}\) to kWh.
5. Convert \(1.8\times10^9\text{ J}\) to kWh.
6. If electricity costs 0.15 per kWh, estimate the cost of \(18{,}000{,}000\text{ J}\).

Joules to kWh FAQ