This GCSE physics equation list is designed as a working reference, not just a sheet to memorise the night before an exam. You will find the main formulas students use most often, the meaning of each symbol, the standard units, simple rearrangements, and most importantly a quick guide to when each formula is the right one to choose. Used well, a formula sheet becomes a decision tool: it helps you match a question to the correct model, convert units before you calculate, and avoid common mistakes such as mixing up speed and velocity or charge and current.
Overview
A strong GCSE physics revision sheet does three jobs at once. First, it reminds you of the formula. Second, it shows the correct units so you can keep quantities consistent. Third, it tells you what sort of situation the formula describes.
That third job is the one students often miss. Many marks are lost not because the equation was forgotten, but because the wrong one was chosen. A useful equation list should therefore answer four questions quickly:
- What does each symbol mean?
- What units should I use?
- How can I rearrange the equation?
- When should I use this rather than a similar formula?
Below is a practical GCSE-focused reference organised by topic. Exact exam-board wording can differ, so treat this as a durable study guide and compare it with your own specification before an assessment.
How to use this page
- Read the question and identify the topic: motion, forces, energy, electricity, waves, or density and pressure.
- Underline the given quantities and write down their units.
- Choose a formula that contains the unknown and the values you already have.
- Rearrange before substituting numbers if needed.
- Convert units first, not halfway through.
- Check whether your answer is sensible in size and unit.
Core concepts
This section gives the core GCSE physics formulas with units, rearrangements, and decision rules for when to use each one.
Motion and kinematics
Speed
Formula: speed = distance / time
Symbols: v = s / t
Units: speed in m/s, distance in m, time in s
Rearrangements: distance = speed × time, time = distance / speed
Use when: an object’s journey is described in terms of how far it travels over a time interval. Use this for scalar motion questions where direction does not matter.
Velocity is often treated similarly at GCSE level, but remember that velocity includes direction while speed does not. If the question mentions direction, vectors, or displacement, think carefully about whether velocity is intended.
Acceleration
Formula: acceleration = change in velocity / time
Symbols: a = (v - u) / t
Units: acceleration in m/s², velocities in m/s, time in s
Rearrangements: v = u + at, u = v - at, t = (v - u) / a
Use when: the question gives starting velocity, final velocity, and time, or asks how quickly velocity changes.
Forces and Newton's laws
Weight
Formula: weight = mass × gravitational field strength
Symbols: W = mg
Units: weight in N, mass in kg, gravitational field strength in N/kg
Rearrangements: m = W / g, g = W / m
Use when: converting between mass and the force due to gravity. Do not confuse weight with mass.
Resultant force and acceleration
Formula: force = mass × acceleration
Symbols: F = ma
Units: force in N, mass in kg, acceleration in m/s²
Rearrangements: m = F / a, a = F / m
Use when: a net force causes an object to speed up, slow down, or change direction. This is the standard way to connect dynamics and motion.
Momentum
Formula: momentum = mass × velocity
Symbols: p = mv
Units: momentum in kg m/s, mass in kg, velocity in m/s
Rearrangements: m = p / v, v = p / m
Use when: collisions, explosions, recoil, or moving objects are involved.
Change in momentum and force
Formula: force = change in momentum / time
Symbols: F = Δp / t
Units: force in N, momentum in kg m/s, time in s
Rearrangements: Δp = Ft, t = Δp / F
Use when: questions involve stopping distances, airbags, crumple zones, or impact forces.
Energy, work, and power
Work done
Formula: work done = force × distance
Symbols: W = Fs
Units: work in J, force in N, distance in m
Rearrangements: F = W / s, s = W / F
Use when: a force causes movement in its direction. At GCSE, work done and energy transferred often have the same numerical value in joules.
Kinetic energy
Formula: kinetic energy = 1/2 × mass × speed²
Symbols: E_k = 1/2 mv²
Units: energy in J, mass in kg, speed in m/s
Rearrangements: usually easiest to rearrange step by step, for example v = √(2E_k / m)
Use when: an object is moving and the question asks about motion energy.
Gravitational potential energy
Formula: GPE = mass × gravitational field strength × height
Symbols: E_p = mgh
Units: energy in J, mass in kg, g in N/kg, height in m
Rearrangements: h = E_p / (mg), m = E_p / (gh)
Use when: an object is raised above the ground or changes vertical position.
Power
Formula: power = energy transferred / time
Symbols: P = E / t
Units: power in W, energy in J, time in s
Rearrangements: E = Pt, t = E / P
Use when: you are comparing how quickly devices transfer energy.
Electricity
Charge, current, and time
Formula: charge = current × time
Symbols: Q = It
Units: charge in C, current in A, time in s
Rearrangements: I = Q / t, t = Q / I
Use when: electric charge flow is involved.
Potential difference, current, resistance
Formula: voltage = current × resistance
Symbols: V = IR
Units: voltage in V, current in A, resistance in Ω
Rearrangements: I = V / R, R = V / I
Use when: basic circuit analysis, component behaviour, and Ohm’s law questions. For more practice, see Ohm's Law and Basic Circuit Problems: Step-by-Step Practice Set.
Electrical power
Formula: power = current × voltage
Symbols: P = IV
Units: power in W, current in A, voltage in V
Rearrangements: I = P / V, V = P / I
Use when: appliances, power ratings, and energy transfer in circuits are discussed.
Electrical energy transferred
Formula: energy = power × time
Symbols: E = Pt
Units: energy in J, power in W, time in s
Use when: finding how much electrical energy a device uses.
Alternative electrical energy equation
Formula: energy transferred = charge × potential difference
Symbols: E = QV
Units: energy in J, charge in C, voltage in V
Use when: the question is about the energy gained or lost by charges moving through a potential difference.
Waves
Wave speed
Formula: wave speed = frequency × wavelength
Symbols: v = fλ
Units: speed in m/s, frequency in Hz, wavelength in m
Rearrangements: f = v / λ, λ = v / f
Use when: sound, light, water waves, or electromagnetic waves are involved.
Period and frequency
Formula: frequency = 1 / period
Symbols: f = 1 / T
Units: frequency in Hz, period in s
Rearrangements: T = 1 / f
Use when: oscillations or repeated cycles are described.
Density and pressure
Density
Formula: density = mass / volume
Symbols: ρ = m / V
Units: density in kg/m³, mass in kg, volume in m³
Rearrangements: m = ρV, V = m / ρ
Use when: comparing materials or calculating mass from size.
Pressure
Formula: pressure = force / area
Symbols: p = F / A
Units: pressure in Pa, force in N, area in m²
Rearrangements: F = pA, A = F / p
Use when: surfaces, contact forces, cutting tools, snowshoes, or load distribution are discussed.
Efficiency
Efficiency
Formula: efficiency = useful output / total input
It may be expressed for energy or power:
efficiency = useful energy output / total energy input
efficiency = useful power output / total power input
Units: no unit; often given as a decimal or percentage
Use when: devices waste part of the input energy. To convert to a percentage, multiply by 100.
Thermal physics basics
Specific heat capacity
Formula: energy = mass × specific heat capacity × temperature change
Symbols: E = mcΔθ
Units: energy in J, mass in kg, specific heat capacity in J/kg°C, temperature change in °C
Rearrangements: c = E / (mΔθ), Δθ = E / (mc)
Use when: heating substances without a change of state. For related higher-level thermal reference material, see Thermodynamics Formula Sheet: Heat, Work, Internal Energy, and Efficiency.
Related terms
Knowing formulas is easier when the vocabulary is clear. These are the terms that often decide which equation to use.
Scalar and vector: Scalars have magnitude only, such as speed and energy. Vectors have magnitude and direction, such as velocity and force.
Distance and displacement: Distance is total path length. Displacement is the straight-line change in position with direction. If a question stresses direction, displacement-based thinking may matter.
Mass and weight: Mass is the amount of matter, measured in kilograms. Weight is a force caused by gravity, measured in newtons.
Energy and power: Energy is how much is transferred, stored, or used. Power is the rate at which energy is transferred.
Current and charge: Current is the rate of flow of charge. Charge is the total amount that moves.
Potential difference and resistance: Potential difference is energy transferred per unit charge. Resistance describes how much a component opposes current.
Frequency and period: Frequency counts cycles per second. Period is the time for one cycle.
Density and volume: Density tells you how much mass is packed into a given volume.
Resultant force: This is the overall force after combining all forces acting on an object. If forces are balanced, the resultant force is zero.
Students also benefit from seeing how formulas connect across levels. If you plan to continue, the site’s A-Level Physics Revision Notes by Topic and IB Physics Revision Guide show how the same core relationships develop later.
Practical use cases
This section shows how to decide which formula to use in common GCSE situations.
1. A moving car question
If you are given distance and time, use speed = distance / time. If you are given initial and final speed over a time interval, use acceleration = change in velocity / time. If a braking force is involved, consider F = ma or F = Δp / t depending on the data provided.
2. A falling object question
If the question asks for the force of gravity on the object, use W = mg. If it asks about energy gained by being raised, use E_p = mgh. If it asks about motion energy during movement, use E_k = 1/2 mv².
3. A household electricity question
If you know voltage and current, use P = IV for power. If you know power and time, use E = Pt for energy transferred. If you need the relationship between voltage, current, and resistance, use V = IR.
4. A wave question
If frequency and wavelength are known, use v = fλ. If the question gives period instead of frequency, first convert using f = 1 / T.
5. A material or floating object question
If mass and volume are involved, start with density: ρ = m / V. Keep an eye on unit conversions, especially between cm³ and m³.
6. A heating question
If temperature changes but the substance does not change state, use E = mcΔθ. Make sure the temperature change is the difference between final and initial temperature, not the final temperature alone.
Common equation mistakes to avoid
- Using centimetres when the formula needs metres.
- Using grams instead of kilograms.
- Confusing energy and power.
- Forgetting to square the speed in kinetic energy.
- Using total distance when the question is about displacement or direction.
- Rearranging incorrectly by moving terms without applying the same operation properly.
A quick rearrangement method that works
For GCSE, the safest method is usually algebra rather than memorised triangles. Write the original equation clearly, decide what you want to isolate, and reverse the operations step by step. For example, from V = IR, to make R the subject, divide both sides by I: R = V / I. This is slower at first but more reliable in exams.
If you want more topic-specific visual explanations, related references on this site include Optics Ray Diagrams Explained, Simple Harmonic Motion Explained, and Magnetic Force and Fields.
When to revisit
Come back to this equation list whenever your revision changes from learning content to solving problems. In practice, that usually means four moments:
- At the start of a topic: use it to see the small set of relationships that organise the whole chapter.
- During homework: use it to choose equations and check units before calculating.
- Before mocks or final exams: use it as a compact gcse physics revision sheet and test whether you can explain when each formula applies.
- When marks are being lost repeatedly: use it diagnostically to spot whether the problem is memory, units, rearrangement, or formula selection.
A practical revision habit is to turn this page into a personal formula checklist. Next to each equation, mark one of three states: know it, can rearrange it, can choose it under pressure. That last category matters most.
For a final pass before assessments, pair formula review with worked questions and your own error log. If you also study other programmes, compare this page with the site’s AP Physics Revision Hub to see how formula use broadens with more advanced problem solving.
Action step: copy the equations you use least confidently onto one page, add units beside every symbol, and write one short note under each formula starting with “Use this when...”. That turns memorisation into recognition, which is exactly what exam questions demand.
