GCSE Maths Formulas You Need to Memorise
June 19, 2026
Some GCSE Maths formulas are given in the exam — but many are not, and you are expected to know them by heart. Forgetting one can cost you several marks. This guide lists the key formulas to memorise and the most effective way to learn them.
Formulas you must memorise (not given)
Since the formulae sheets introduced during the pandemic were withdrawn, you are back to memorising almost everything. A small number of formulas are still printed on the exam paper itself, and which ones varies between AQA, OCR and Edexcel — check the front of a recent past paper for your board. Everything below, assume you need to know by heart.
Foundation and Higher — both tiers
| What | Formula | Watch out for |
|---|---|---|
| Area of a circle | A = πr² | Square the radius, not the diameter |
| Circumference | C = 2πr = πd | Two versions — know which you have |
| Area of a triangle | A = ½ × b × h | Height is perpendicular, not a slanted side |
| Area of a trapezium | A = ½(a + b)h | a and b are the parallel sides |
| Pythagoras | a² + b² = c² | c is always the hypotenuse; subtract when finding a shorter side |
| Trigonometry | SOH CAH TOA | Right-angled triangles only |
| Speed | speed = distance ÷ time | Convert minutes to hours before dividing |
| Density | density = mass ÷ volume | Check the units match the answer line |
| Pressure | pressure = force ÷ area | Area in m² for pascals |
| Percentage change | (change ÷ original) × 100 | Always divide by the original amount |
| Compound interest | P × (multiplier)n | 5% rise → ×1.05; 5% fall → ×0.95 |
Higher tier only
| What | Formula | Watch out for |
|---|---|---|
| Quadratic formula | x = [−b ± √(b² − 4ac)] ÷ 2a | The −b and the ÷2a cover the whole expression |
| Sine rule | a ÷ sin A = b ÷ sin B | Flip it when finding an angle |
| Cosine rule | a² = b² + c² − 2bc cos A | Angle A must be opposite side a |
| Area of any triangle | A = ½ab sin C | C is the angle between a and b |
| Volume of a sphere | V = 4/3 πr³ | Cube the radius |
| Volume of a cone | V = ⅓ πr²h | h is vertical height, not slant height |
| Curved surface area of a cone | A = πrl | l is the slant height |
The three that cost the most marks are the cosine rule (using the wrong angle), compound interest (adding the percentage each year instead of multiplying) and the cone volume (reaching for the slant height because it is the number printed on the diagram).
Why flashcards are perfect for this
Formulas are exactly the kind of small, self-contained facts that flashcards excel at. Put the name of the formula on the front and the formula on the back, then test yourself repeatedly. With spaced repetition, you spend more time on the ones you keep forgetting.
How to practise them
Don't just read the formulas — recall them. Cover the answer, write the formula from memory, then check. Once you can recall it, apply it to a past-paper question so you can both remember and use it under pressure.
BrightRevision's GCSE Maths flashcards cover the formulas and methods for both Foundation and Higher, using spaced repetition so the ones you struggle with come up more often.
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