GCSE Conversion Tools 2025: The Ultimate Guide to Unit Conversions, Grade Comparisons, and Smart Study Workflows

GCSE 9–1 ↔ A*–G Conversion Tool

9=highest • 4≈C (standard pass) • 7≈A (lower) • 1≈G (lower)

Quick convert (single grade)

Equivalence band: —

Subjects (batch convert)

Add your GCSEs and choose numeric grades. The tool converts them to old‑style A*–G under the selected policy. Counts strong/standard passes and exports a CSV.
#Subject9–1LetterBandPass TypeActions
Add subjects to see a summary.
Strong passes (5+): —
Standard passes (4+): —
Total subjects: —

Mapping (editable bands: lower ↔ higher letter)

9–1Lower letterHigher letter
Defaults mirror widely used guidance: 9→A*, 8→A*/A, 7→A, 6→B, 5→C/B ("strong pass"), 4→C ("standard pass"), 3→E/D, 2→F/E, 1→G/F, U→U. This is an equivalence aid, not official grade boundaries.

Introduction: why “conversion” is a bigger deal than it looks

Every GCSE student hits the same two friction points:

  1. Unit conversions (Maths & Physics): centimetres to metres, grams to kilograms, Joules to kilowatt-hours, electron-volts to Joules—plus the perpetual puzzles of significant figures and standard form.

  2. Grade/system conversions (beyond GCSE): translating results for other frameworks (IB, MYP, SAT, National 5, CBSE) when you’re applying internationally or switching schools.

The phrase gcse conversion covers both worlds. In exams, your ability to convert units quickly and correctly is a quiet superpower—it unlocks marks without fancy theory. In applications, having a defensible way to explain how your GCSE profile maps to another system stops confusion before it starts.

This 2025 guide gives you a complete toolkit:

  • A no-nonsense playbook for conversion gcse maths tasks and gcse physics conversions, with the exact conversions you need to know for gcse maths, memory hooks, and error traps.

  • Copy-ready templates to build your own gcse conversion table and smart calculators in a spreadsheet (or notes app) that auto-check sig figs and units.

  • Practical, policy-aware advice for cross-system comparisons (CBSE, IB/MYP, SAT, National 5)—what you can safely claim, what you mustn’t, and how to present equivalence transparently.

  • A long, keyworded FAQ where each of your required phrases appears as a question with an answer, so you can search this page and jump straight to what you need.

Keep this open while you revise. Conversions aren’t the flashy part of STEM—but they raise grades and reduce panic.


Part 1 — Conversion mindset: three habits that prevent 90% of mistakes

1) Start with dimensions, not numbers.
Before you touch the calculator, write units as algebra:

value×target unitcurrent unit\text{value} \times \frac{\text{target unit}}{\text{current unit}}

Then cancel what you don’t want. This “factor-label method” (a.k.a. dimensional analysis) is the backbone of unit conversion gcse maths and physics questions.

2) Standard form + significant figures = clean answers.

  • Standard form: a×10na \times 10^n where 1a<101 \le a < 10.

  • Sig figs: round to the precision of the least precise measurement used in your calculation (unless the question sets a format).
    Pro tip: do the math in full precision, round once at the end, and label your final units.

3) Build a micro-library you trust.
Keep a one-page crib: base SI units, common prefixes, exact constants you’re allowed to assume, and everyday conversion factors (hours→seconds, cm→m, kWh→J). Your gcse maths unit conversions and gcse physics conversions rely on this much more than on new formulas.


Part 2 — The conversions you need to know for GCSE Maths (and how to remember them)

Core metric ladder (memorise the exponents)

  • kilo kk = 10310^3

  • hecto hh = 10210^2

  • deca dada = 10110^1

  • base (m, g, s, L) = 10010^0

  • deci dd = 10110^{-1}

  • centi cc = 10210^{-2}

  • milli mm = 10310^{-3}

Memory hook: “King Henry Died By Drinking Chocolate Milk.”

Length, area, volume (don’t mix dimensions)

  • Length: 1km=1000m1\,\text{km}=1000\,\text{m}; 1m=100cm1\,\text{m}=100\,\text{cm}; 1cm=10mm1\,\text{cm}=10\,\text{mm}.

  • Area: scale factor squared. 1m2=104cm21\,\text{m}^2=10^4\,\text{cm}^2.

  • Volume: scale factor cubed. 1m3=106cm31\,\text{m}^3=10^6\,\text{cm}^3.

  • Volume ↔ capacity: 1L=1dm3=1000cm31\,\text{L}=1\,\text{dm}^3=1000\,\text{cm}^3; 1mL=1cm31\,\text{mL}=1\,\text{cm}^3.

Mass, time, speed, density

  • Mass: 1kg=1000g1\,\text{kg}=1000\,\text{g}; 1g=1000mg1\,\text{g}=1000\,\text{mg}.

  • Time: 1min=60s1\,\text{min}=60\,\text{s}; 1h=3600s1\,\text{h}=3600\,\text{s}.

  • Speed: 1m s1=3.6km h11\,\text{m s}^{-1}=3.6\,\text{km h}^{-1}.

  • Density: 1g cm3=1000kg m31\,\text{g cm}^{-3}=1000\,\text{kg m}^{-3}.

Angles & trig defaults

  • Degrees↔radians appear rarely at GCSE: πrad=180\pi\,\text{rad}=180^\circ. If radians surface in extension, know θrad=θ×π180\theta_\text{rad}=\theta_\circ \times \frac{\pi}{180}.

Probability & percentages

  • Percents: divide by 100; percentage change =newoldold×100%=\frac{\text{new}-\text{old}}{\text{old}}\times 100\%.

  • Multipliers: 20% increase → ×1.20\times 1.20; 15% decrease → ×0.85\times 0.85.
    These aren’t “conversions” in the unit sense, but they’re routine score-lifters.


Part 3 — GCSE Physics conversions you’ll use constantly

Energy & power

  • Joules ↔ kilowatt-hours:
    1kWh=1000W×3600s=3.6×106J1\,\text{kWh}=1000\,\text{W}\times 3600\,\text{s}=\mathbf{3.6\times10^6\,J}.
    To convert E[J]E\,[\text{J}] to kWh: E/3.6×106E/3.6\times 10^6.

  • Electron-volt: 1eV=1.602×1019J1\,\text{eV}=\mathbf{1.602\times10^{-19}\,J}.
    Use when photons or particle energies show up (extension topics or Combined Science higher).

  • Power: P=E/tP=E/t. Keep units coherent (J, s, W). 1 W = 1 J s1^{-1}.

Electricity

  • Charge: Q=ItQ=It; 1 Coulomb = 1 A·s.

  • Potential difference: V=W/QV=W/Q (J/C).

  • Resistance: R=V/IR=V/I (Ω).

  • Energy in circuits: E=V or E=I2RtE=I^2Rt or E=V2RtE=\frac{V^2}{R}t.
    Convert hours→seconds and mA→A, kΩ→Ω before calculating.

Waves & optics

  • Wave speed: v=fλv=f\lambda (m/s, Hz, m).

  • Frequency ↔ period: f=1/Tf=1/T, TT in seconds.

Pressure, moments, density

  • Pressure: p=F/Ap=F/A (Pa = N/m²). 1kPa=1000Pa1\,\text{kPa}=1000\,\text{Pa}.

  • Moments: M=FdM=Fd (N·m). Keep dd in metres.

  • Density: ρ=m/V\rho = m/V (kg/m³). Convert cm³→m³ with 10610^{-6}.

Thermal & specific heat

  • Q=mcΔTQ=mc\Delta T. Units: J, kg, J kg1^{-1} K1^{-1}, K/°C.

  • Latent heat: Q=mLQ=mL (J/kg).

Sanity checks for physics conversions:

  • If an answer for speed is > 3×10⁸ m/s, you’ve almost certainly left hours instead of seconds or km instead of m.

  • For densities: water ≈ 1000kg m31000\,\text{kg m}^{-3}. If you get 10610^6 for water, you forgot the cube when converting cm to m.


Part 4 — Build your own GCSE conversion table and calculator (15-minute setup)

The goal: a single sheet where you type any number with its current unit and get the target unit instantly—plus quick toggles for sig figs and standard form. You can do this in Google Sheets, Excel, or even a note app with a little manual math.

Step A: Create a gcse conversion table of factors

Make a 2-column list:

From → ToFactor (multiply by)
mm → m0.001
cm → m0.01
km → m1000
g → kg0.001
kWh → J3,600,000
eV → J1.602E-19
cm³ → m³1E-6
L → m³0.001
m/s → km/h3.6
kPa → Pa1000

Add as many as you want. Keep area and volume separately with squared/cubed factors (e.g., m²↔cm², m³↔cm³).

Step B: Simple lookup formula

Have inputs:

  • Value (number)

  • From unit (drop-down)

  • To unit (drop-down)

Then compute:

 
= Value * XLOOKUP(From & " → " & To, Table[Pair], Table[Factor])

If your software doesn’t have XLOOKUP, use INDEX/MATCH or VLOOKUP with a helper key.

Step C: Sig figs helper

  • A quick UX trick: include a cell SigFigs (1–6) and use a rounding function:

 
=TEXT( ConvertedValue, "0." & REPT("0", SigFigs-1) )

Or use a custom function/ROUND with LOG10 to keep sig figs programmatically. When in doubt, round by hand after you see the raw output.

Step D: Standard form display

For display only (not for calculation):

 
=TEXT( ConvertedValue, "0.00E+00" )

Adjust the zeros to the number of dp you want to show.

Step E: Error guards

  • If From = To, return the same number.

  • If the pair doesn’t exist, return “Add this conversion to the table.”

  • For physics, show a unit reminder: “Remember to convert hours to seconds.”

Result: your personal gcse conversion hub. You’ll use it every week.


Part 5 — Worked examples you can copy

Maths example 1 — Compound “area then scale” trap

Question: A square has side 12cm12\,\text{cm}. Find its area in m2\text{m}^2.
Wrong instinct: 122=14412^2=144 then divide by 100.
Right path: Convert length first: 12cm=0.12m12\,\text{cm}=0.12\,\text{m}. Area =0.122=0.0144m2=0.12^2=0.0144\,\text{m}^2.
Lesson: Areas scale with the square of the factor.

Maths example 2 — Speed units

Question: Convert 5m s15\,\text{m s}^{-1} to km/h.
Solution: 5×3.6=18km h15 \times 3.6=18\,\text{km h}^{-1}.

Physics example 1 — Electricity bill estimate

A 2 kW heater runs for 3 h.

  • Energy E=2kW×3h=6kWhE = 2\,\text{kW} \times 3\,\text{h}=6\,\text{kWh}.

  • In Joules: 6×3.6×106=2.16×107J6 \times 3.6\times 10^6 = 2.16\times 10^7 \,\text{J}.

Physics example 2 — Photon energy

Photon: E=2.5eVE = 2.5\,\text{eV}. Convert to Joules.
E=2.5×1.602×10194.01×1019JE = 2.5 \times 1.602\times 10^{-19} \approx 4.01\times 10^{-19}\,\text{J}.
Rounded to 2 sig figs: 4.0×1019J4.0 \times 10^{-19}\,\text{J}.

Physics example 3 — Density switch

A sample has mass 15g15\,\text{g} and volume 12cm312\,\text{cm}^3. Find ρ\rho in kg m3\text{kg m}^{-3}.
ρ=15g12cm3=1.25g cm3=1.25×1000=1250kg m3\rho = \frac{15\,\text{g}}{12\,\text{cm}^3} = 1.25\,\text{g cm}^{-3} = 1.25 \times 1000 = 1250\,\text{kg m}^{-3}.
(You multiplied by 1000 because 1g cm3=1000kg m31\,\text{g cm}^{-3}=1000\,\text{kg m}^{-3}.)


Part 6 — Cross-system grade conversions (pro tips and guardrails)

Before the comparisons: there is no single global official conversion. Universities and schools apply their own rules. Your job is to present clear, honest context:

  • Say which table you’re using (e.g., “Indicative mapping commonly used by international schools—check programme-specific requirements”).

  • Prefer bands (ranges) to single-point equivalences.

  • Never inflate. Provide the original GCSE scores alongside any mapping.

Indicative GCSE 9–1 ↔ legacy letter grades

  • 9 ≈ high A*

  • 8 ≈ low A*/high A

  • 7 ≈ A

  • 6 ≈ high B

  • 5 ≈ strong pass (B/C)

  • 4 ≈ standard pass (C)

  • 3 ≈ D/E

  • 2 ≈ E/F

  • 1 ≈ F/G

  • U = ungraded

Use this for family explanations; it is not how universities make decisions, but it helps non-UK readers.

GCSE ↔ IB (Diploma or MYP) — illustrative guidance

  • GCSE to IB conversion (DP context): A common indicative vibe is

    • GCSE 9 → roughly IB 7 potential in the subject,

    • 8 → 6–7,

    • 7 → 6,

    • 6 → 5,

    • 5 → 4.
      This is predictive, not a rule; actual IB grades depend on IB assessments.

  • IB to GCSE conversion (reverse):

    • IB 7 ≈ GCSE 9,

    • IB 6 ≈ 8/7,

    • IB 5 ≈ 6/5,

    • IB 4 ≈ 5/4.
      Again, indicative only.

  • MYP to GCSE conversion: many schools map

    • MYP 7 → GCSE 9,

    • 6 → 8,

    • 5 → 7/6,

    • 4 → 5/4,

    • 3 → 3/2,

    • 2 → 2/1,

    • 1 → 1.
      Check your school’s published policy; they vary.

GCSE ↔ National 5 (Scotland)

  • National 5 is broadly comparable in level to GCSE (both are typical age-16 qualifications). A rough grade sense many advisors use:

    • Nat 5 A ≈ GCSE 7–9,

    • Nat 5 B ≈ GCSE 6,

    • Nat 5 C ≈ GCSE 4–5.
      Use ranges; the syllabi and assessments are different.

GCSE ↔ SAT (US)

  • There is no official gcse to sat conversion. The SAT is a standardised aptitude/achievement test (Math and Evidence-Based Reading & Writing). Admissions teams look at GCSEs and SAT separately. If you must contextualise: strong GCSE Maths/English (7–9) tends to accompany higher SAT section scores, but you shouldn’t claim numeric equivalence.

GCSE ↔ CBSE (India)

  • cbse to gcse conversion is institution-specific. Some schools use percentage bands like:

    • CBSE 91–100% ≈ GCSE 9,

    • 81–90%8,

    • 71–80%7,

    • 61–70%6, etc.
      These are illustrative. Always attach the original CBSE mark sheet and the school’s official conversion note if available.

Bottom line: When you present a cross-system mapping, attach your source (school policy, programme guide, or “indicative for counselling only”) and keep your original GCSE results front-and-centre.


Part 7 — Common pitfalls (so you don’t donate marks to the examiners)

  1. Converting area/volume like length.
    Fix: square or cube the scale factor.

  2. Mixing grams and kilograms inside density/force equations.
    Fix: convert before substituting. Keep SI base units consistent.

  3. Time left in hours inside power equations.
    Fix: multiply hours by 3600 when using E=PtE=Pt in Joules.

  4. Over-rounding mid-calculation.
    Fix: round once at the end; carry 3–4 sig figs through the working.

  5. Forgetting unit labels in final answers.
    Fix: write units at the start and carry them through; examiners award method marks for correct unit handling.

  6. Treating cross-system grade “equivalences” as official.
    Fix: declare mappings as indicative and include original grades.


Part 8 — A compact “conversions you need to know for gcse maths” crib

  • Lengths: mm↔cm↔m↔km (powers of 10).

  • Areas: 1m2=104cm21\,\text{m}^2=10^4\,\text{cm}^2.

  • Volumes: 1m3=106cm31\,\text{m}^3=10^6\,\text{cm}^3, 1L=1dm3=1000cm31\,\text{L}=1\,\text{dm}^3=1000\,\text{cm}^3.

  • Mass: kg↔g↔mg.

  • Speed: 1m s1=3.6km h11\,\text{m s}^{-1}=3.6\,\text{km h}^{-1}.

  • Density: 1g cm3=1000kg m31\,\text{g cm}^{-3}=1000\,\text{kg m}^{-3}.

  • Energy: 1kWh=3.6×106J1\,\text{kWh}=3.6\times 10^6\,\text{J}.

  • Power: W = J/s.

  • Pressure: Pa = N/m²; kPa×1000 = Pa.

  • Angles: πrad=180\pi\,\text{rad}=180^\circ (rare but useful).

  • Standard form & sig figs rules.

Paste this into your notes or the top of your exam paper (when allowed) as a mental checklist.


Part 9 — Study workflow: turn conversions into free marks

  • Make a 1-page sheet (A4) with your personal gcse conversion table, sig-fig notes, and three worked examples you always forget.

  • Practice “unit-first”: in every physics calculation, convert all quantities to SI before doing the maths.

  • Daily 5-minute drill: pick three random conversions (one length/area/volume, one physics energy/electricity, one speed/density). Time yourself.

  • Error journal: when you miss a unit, write a one-line “why.” Most students fix the same three mistakes repeatedly.

  • For cross-system needs: draft a one-paragraph explanation of your grades with the indicative mapping and a link/reference to your school’s policy; reuse it for applications.


FAQ (each question uses your exact keyword phrase)

“gcse conversion” — what does it cover and why does it matter?

Answer: The term gcse conversion covers two domains: (1) unit conversions needed for Maths and Physics calculations, and (2) grade/system conversions when you compare GCSE results with other frameworks (IB, SAT, National 5, CBSE, etc.). Unit conversions protect easy marks; grade conversions help you present your achievements clearly to international schools and universities. Always treat cross-system mappings as indicative, not official.

“conversion gcse maths” — what’s the fastest reliable method?

Answer: For conversion gcse maths, use the factor-label method. Write the quantity with its unit and multiply by conversion factors as fractions so units cancel:

value×targetcurrent\text{value} \times \frac{\text{target}}{\text{current}}

Convert lengths directly, areas with the factor squared, and volumes with the factor cubed. Round once at the end to the correct significant figures.

“gcse maths unit conversions” — which ones show up most?

Answer: The most common gcse maths unit conversions are: mm↔cm↔m↔km; cm²↔m²; cm³↔m³; mL↔L↔cm³↔dm³; g↔kg↔mg; m/s↔km/h; and density g/cm3kg/m3\text{g/cm}^3 \leftrightarrow \text{kg/m}^3. Also expect percentage multipliers and standard form tidying.

“gcse physics conversions” — what should I memorise?

Answer: For gcse physics conversions, lock in: 1kWh=3.6×106J1\,\text{kWh}=3.6\times10^6\,\text{J}; 1eV=1.602×1019J1\,\text{eV}=1.602\times10^{-19}\,\text{J}; 1Pa=1N/m21\,\text{Pa}=1\,\text{N/m}^2; 1m/s=3.6km/h1\,\text{m/s}=3.6\,\text{km/h}; 1C=1A\cdotps1\,\text{C}=1\,\text{A·s}; 1g/cm3=1000kg/m31\,\text{g/cm}^3=1000\,\text{kg/m}^3. And always convert hours→seconds, cm→m before using formulas.

“unit conversion gcse maths” — how do I avoid area/volume traps?

Answer: In unit conversion gcse maths, convert length first, then calculate area/volume. Example: square side 12cm=0.12m12\,\text{cm}=0.12\,\text{m}; area =0.122=0.0144m2=0.12^2=0.0144\,\text{m}^2. If you square after converting the area units directly, you’ll be off by factors of 100 or 10,000.

“cbse to gcse conversion” — what’s a safe way to present it?

Answer: For cbse to gcse conversion, use ranges and source a published school policy if possible. An indicative pattern some schools adopt is CBSE 91–100% ≈ GCSE 9; 81–90% ≈ 8; 71–80% ≈ 7; and so on. Declare it as illustrative, include your original mark sheet, and note that universities apply their own evaluations.

“conversions you need to know for gcse maths” — can I get a one-page list?

Answer: Yes—see the crib in Part 8. The conversions you need to know for gcse maths include the metric ladder (kilo↔milli), area/volume scaling, capacity↔volume (1 L = 1 dm³ = 1000 cm³), mass, speed, density, pressure, kWh↔J, and standard form + sig-fig rules.

“gcse conversion table” — what should it look like?

Answer: A gcse conversion table for units is a two-column list of From→To pairs with multiply-by factors (e.g., cm→m ×0.01; kWh→J ×3,600,000). Keep separate sub-tables for area and volume. If you’re making a grade comparison table, label it indicative and include your source (school policy). Do not claim it is official across all universities.

“gcse to ib conversion” — is there a direct mapping?

Answer: There is no universal gcse to ib conversion. A common counselling shorthand is GCSE 9 ≈ IB 7 potential in that subject; 8 ≈ 6–7; 7 ≈ 6; 6 ≈ 5; 5 ≈ 4. It’s predictive and not a guarantee. Present your GCSE grades and any school-approved prediction policy together.

“gcse to sat conversion” — can I convert my scores?

Answer: There is no official gcse to sat conversion. Admissions read GCSEs (curriculum grades) and SAT (standardised test) separately. If asked, provide your GCSE profile and SAT score report, not a numeric equivalence.

“ib to gcse conversion” — how would I explain an IB result to a GCSE audience?

Answer: For ib to gcse conversion, use an indicative band: IB 7 ≈ GCSE 9; 6 ≈ 8/7; 5 ≈ 6/5; 4 ≈ 5/4. Include the IB context (HL/SL, internal assessments) and avoid rigid one-to-one claims.

“myp to gcse conversion” — what’s typical?

Answer: myp to gcse conversion often follows a school-specific table like: MYP 7 → GCSE 9; 6 → 8; 5 → 7/6; 4 → 5/4; 3 → 3/2; 2 → 2/1; 1 → 1. State your source (school policy) and keep original MYP levels visible.

“national 5 equivalent to gcse” — how do they compare?

Answer: national 5 equivalent to gcse is broadly: National 5 A ≈ GCSE 7–9, B6, C4–5. This is a general guide; specific course content and assessments differ. Use ranges and include the original certificate.