Energy Conversion Calculators – Joules, kJ, BTU, Calories, kWh, eV & More
Instantly convert energy units for science, engineering, physics, and nutrition: joules, kilojoules, kWh, BTU, calories, kcal, and electronvolts (eV/keV/MeV/GeV). Energy conversion tools for STEM and daily life.
Popular Energy Unit Conversions
Joules ⇄ kJ
Metric: joules to kilojoules, and back—lab ready.
Joules ⇄ BTU
Physics/engineering: joules to British Thermal Units.
Joules ⇄ Calories
Nutrition/science: joules and small calorie (cal) switch.
Joules ⇄ kcal
Joules to kilocalories (used in diet, fitness, energy).
Joules ⇄ kWh
Joules and kilowatt-hours: appliances, power, utility bills.
Joules ⇄ eV
Physics: joules and electronvolts for atomic/particle energy.
kJ ⇄ Joules
Quick metric kilojoule ↔ joule conversions.
kJ ⇄ BTU
kJ and BTU for heating/cooling calculations.
kJ ⇄ Calories
Food energy: kJ and small calorie equivalents.
kJ ⇄ kcal
International labeling: kilojoules and kilocalories.
BTU ⇄ kJ
BTU and kilojoules for global HVAC/energy standards.
BTU ⇄ Joules
British/metric conversion for labs, engineering, HVAC.
BTU ⇄ kWh
Energy billing: BTU to kilowatt-hours and back.
kWh ⇄ BTU
Electrical heating/cooling power, US vs metric.
kWh ⇄ Joules
Kilowatt-hour to joules for engineers, scientists, utilities.
Calories ⇄ Joules
Calories/joules for fitness, chemistry, biology, food.
Calories ⇄ kJ
Unify metric food labels, convert from nutrition sources.
Calories ⇄ kcal
Switch between small calorie and kilocalorie (Cal).
kcal ⇄ Calories
Reverse food energy conversion for labels, science.
kcal ⇄ Joules
Diet/joules interconversion for food, exercise, research.
kcal ⇄ kJ
Metric conversion for diet notes/food packaging.
eV ⇄ Joules
Energy in particle physics & electrical science.
eV ⇄ keV
Electronvolts and kiloelectronvolts for micro/physics.
eV ⇄ MeV
Convert eV to mega-electronvolts (nuclear/atomic).
eV ⇄ GeV
Convert electronvolts to giga-electronvolts for advanced research.
keV ⇄ eV
Kiloelectronvolt to electronvolt for precise conversions.
MeV ⇄ eV
For nuclear, high-energy and quantum scale calculations.
GeV ⇄ eV
Giga to base electronvolt (particle physics, big science).