SUVAT Calculator (GCSE & A-Level) – With Steps

Stuck on a motion question and not sure which SUVAT equation to use? Enter exactly 3 known values below.

Distance with direction
Starting speed
Ending speed
Rate of velocity change
Duration of motion
Quick Presets:

How to Use This SUVAT Calculator

Follow these quick steps to find your missing motion variables:

  1. Enter any 3 known values. For example, type in your initial velocity (u), acceleration (a), and time (t).
  2. Leave the 2 unknown values blank. Do not put a zero unless the value is actually zero (like starting from rest).
  3. Choose units and sign direction. Make sure to pick a positive direction (e.g., standard up is positive) and keep your signs consistent. Use the gravity helper if needed.
  4. Click Calculate to reveal the missing values and step-by-step mathematical working.

What Does SUVAT Mean?

The letters SUVAT stand for the 5 kinematic variables used to describe motion:

  • s = Displacement (the shortest straight-line distance with a specific direction)
  • u = Initial velocity (the starting speed in a given direction)
  • v = Final velocity (the ending speed)
  • a = Acceleration (the constant rate at which velocity changes)
  • t = Time taken for the motion to occur

SUVAT Equations Used

This calculator automatically chooses the right equation from the five standard equations of motion:

  • v = u + at
  • s = ut + ½at²
  • s = vt - ½at²
  • v² = u² + 2as
  • s = ½(u + v)t

When Should You Use SUVAT?

SUVAT formulas only apply to straight-line motion with constant acceleration. This includes typical physics problems like vehicles braking, trains accelerating uniformly, or objects undergoing free fall due to gravity (ignoring air resistance).

Common Mistakes to Avoid

  • Assuming acceleration is always constant: Do not use these equations for variable acceleration problems. Use calculus instead.
  • Mixing up distance and displacement: Displacement is a vector. If you travel forward 10m and backward 5m, your distance is 15m, but your displacement (s) is 5m.
  • Forgetting negative signs: If an object is moving forward but slowing down, its acceleration must be negative relative to its velocity.
  • Unit mismatches: Ensure all variables are properly converted (e.g., don't mix km/h with m/s²). This tool handles standard conversions for you natively.

SUVAT Calculator FAQs

What is a SUVAT calculator?
A SUVAT calculator is a tool that computes kinematics problems involving constant acceleration. By entering any three known parameters of an object's motion, it resolves the remaining two parameters mathematically.
How many values do I need to enter?
You must enter exactly 3 known values. The formulas require 3 variables to guarantee a solution for the remaining 2 unknowns.
Can I use this for GCSE and A-Level Physics?
Yes. This calculator applies the exact equations of motion taught in UK GCSE Physics, A-Level Physics, and A-Level Maths Mechanics syllabuses.
Why do I sometimes get two answers?
Some equations involve a square root (like v² = u² + 2as) which can produce a positive and negative mathematical solution. Depending on the scenario, one or both may be physically possible.
Why is gravity sometimes negative?
Gravity is a downward acceleration. If you establish the "upward" direction as positive, gravity must be entered as a negative value (e.g., -9.81 m/s²). If you define "downward" as positive, gravity is positive. Consistency is key!
Can I use km/h or mph?
Yes, the tool supports internal unit conversions for miles per hour, kilometres per hour, feet, miles, and minutes.
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