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Revision guideFoundation and Higher

GCSE maths formulas: know them, and know when to use them

For GCSE maths exams in 2026 and 2027 you're given a formulae sheet. That helps, but the sheet won't tell you which formula a question needs, or how to use it. Here are the formulas you'll use most, with what each one is for.

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About the formulae sheet. GCSE maths papers in 2025, 2026 and 2027, including the November resits, come with a formulae sheet, and Foundation and Higher get different sheets. Plans for later years may change. Download your exam board's sheet and get to know it before the exam.

01 / Area and perimeterBoth tiers

Area and perimeter

Rectangle

Area = length × width

Perimeter is the distance all the way round: add up every side.

Both tiers

Triangle

Area = ½ × base × height

The height must be at right angles to the base, not the sloping side.

Both tiers

Parallelogram

Area = base × height

Again, the perpendicular height, not the slanted edge.

Both tiers

Trapezium

Area = ½(a + b)h

a and b are the parallel sides, h is the height between them.

Both tiers

Circle

Circumference = πd = 2πr
Area = πr2

Use the radius for area. If you're given the diameter, halve it first.

Both tiers

Arcs and sectors

Arc length = θ⁄360 × 2πr
Sector area = θ⁄360 × πr2

θ is the angle at the centre. It's just a fraction of the whole circle.

Both tiers

02 / Volume and surface areaBoth tiers

Volume and surface area

Prism

Volume = area of cross-section × length

Works for any shape with the same cross-section all the way through, including cuboids.

Both tiers

Cylinder

Volume = πr2h
Curved surface = 2πrh

It's a prism with a circle for its cross-section.

Both tiers

Pyramid and cone

Volume = ⅓ × base area × height
Cone: ⅓πr2h

A cone's curved surface is πrl, where l is the slant height.

Both tiers

Sphere

Volume = 4⁄3πr3
Surface area = 4πr2

Hemisphere? Halve the volume, and remember the flat circle on top for surface area.

Both tiers

03 / TrianglesRight-angled and beyond

Pythagoras and trigonometry

Pythagoras' theorem

a2 + b2 = c2

Right-angled triangles only. c is the hypotenuse, the longest side, opposite the right angle.

Both tiers

Trigonometry (SOHCAHTOA)

sin x = opp⁄hyp · cos x = adj⁄hyp · tan x = opp⁄adj

Use it when a right-angled triangle question involves an angle.

Both tiers

Sine rule

a⁄sin A = b⁄sin B = c⁄sin C

For triangles without a right angle, when you know a side and its opposite angle.

Higher only

Cosine rule

a2 = b2 + c2 − 2bc cos A

When you know two sides and the angle between them, or all three sides.

Higher only

Area of any triangle

Area = ½ab sin C

C is the angle between sides a and b.

Higher only

04 / AlgebraGraphs and equations

Algebra and graphs

Straight line

y = mx + c

m is the gradient and c is where the line crosses the y-axis.

Both tiers

Gradient

Gradient = change in y⁄change in x

Up is positive, down is negative. Read it from two clear points on the line.

Both tiers

Quadratic formula

x = (−b ± √(b2 − 4ac)) ÷ 2a

For ax2 + bx + c = 0 when it won't factorise neatly.

Higher only

Circle on a graph

x2 + y2 = r2

A circle centred at the origin with radius r.

Higher only

05 / Money, rates and probabilityBoth tiers

Money, rates and probability

Percentage change

Change ÷ original × 100

Always divide by the original amount, not the new one. Practise it in percentages.

Both tiers

Simple and compound interest

Simple: P × r⁄100 × n
Compound: P(1 + r⁄100)n

P is the starting amount, r the rate in %, n the number of years.

Both tiers

Speed, density, pressure

Speed = distance ÷ time
Density = mass ÷ volume
Pressure = force ÷ area

Check the units match before you divide.

Both tiers

Probability

P(not A) = 1 − P(A)
Independent: P(A and B) = P(A) × P(B)

All the probabilities of every possible outcome add up to 1.

Both tiers

06 / Make them stickNot flashcards alone

How to learn formulas so you can use them

  1. Use them in questions

    Reciting a formula isn't the hard part. Choosing it is. Do questions where you have to pick the right one.

  2. Spot the clue words

    "Hypotenuse" or a missing side in a right-angled triangle points to Pythagoras. An angle in a right-angled triangle points to trigonometry.

  3. Write them from memory

    Once a week, write out every formula you can remember, then check. The gaps tell you what to practise.

07 / QuestionsAll questions

Formulas, answered

Do you get a formula sheet in GCSE maths?

For exams in 2025, 2026 and 2027, yes. GCSE maths papers in those years, including the November resits, come with a formulae sheet, and Foundation and Higher have different sheets. Plans for later years may change, so check with your exam board.

Do I still need to learn the formulas?

It still helps a lot. The sheet gives you the formula, but not which one a question needs or how to use it. Knowing them well also saves time in the exam.

Which GCSE maths formulas are Higher only?

The sine rule, the cosine rule, the area of a triangle using ½ab sin C, the quadratic formula and the equation of a circle are Higher only. The other formulas on our formulas page are on both tiers.

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