Speed, Distance and Time Calculator

GCSE PhysicsAQAEdexcelOCRFoundation & Higher

Find speed, distance or time using s = v t. Enter kilometres, minutes or hours if that's what the question gives; the solver converts them to metres and seconds and shows the working.

Quick answer

Speed = distance ÷ time. Use distance in metres and time in seconds to get m/s. For example, a cyclist who travels 1800 m in 300 s has a speed of 1800 ÷ 300 = 6 m/s.

By Mehmood Kakar · Updated

s = v × t
Find:

How to calculate speed, distance and time

Speed tells you how far something travels each second. On your equation sheet it is written as:

distance travelled = speed × time

  • s is distance in metres (m)
  • v is speed in metres per second (m/s)
  • t is time in seconds (s)

Rearranged, the equation gives speed = distance ÷ time and time = distance ÷ speed. Most marks are lost on units: a journey of 3 km in 10 minutes must become 3000 m in 600 s before you divide, which gives 5 m/s.

The speed you calculate this way is the average speed over the whole journey. Real objects speed up and slow down, so their speed at any moment can be higher or lower.

Speed has no direction. Velocity is speed in a given direction, and questions about changes in velocity use the acceleration equation instead.

Some typical speeds are worth knowing, because an exam may ask you to estimate: walking is about 1.5 m/s, running about 3 m/s, cycling about 6 m/s and sound in air about 330 m/s.

Common mistakes that cost marks

  1. Not converting minutes or hours. 5 minutes is 300 s and 1.5 hours is 5400 s. Convert before you calculate.
  2. Not converting kilometres. 120 km is 120,000 m. Mixing km with seconds gives a speed in km/s, not m/s.
  3. Dividing the wrong way round. Speed is distance ÷ time. If your answer for a car is 0.04 m/s, you have probably divided time by distance.
  4. Giving a km/h answer when m/s is asked for. Divide km/h by 3.6 to get m/s.
  5. Forgetting the unit. Write m/s, m or s on every answer.

Practice questions

Try each one on paper first, then reveal the worked answer.

Q1A cyclist travels at a steady 6.0 m/s for 5 minutes. Calculate the distance she travels.[3 marks]
  1. Convert: t = 5 min × 60 = 300 s
  2. s = v × t
  3. s = 6.0 × 300
  4. s = 1800 m
Q2A train travels 120 km in 1.5 hours. Calculate its average speed in m/s.[3 marks]
  1. Convert: s = 120 km × 1000 = 120,000 m
  2. Convert: t = 1.5 h × 3600 = 5400 s
  3. v = s ÷ t = 120,000 ÷ 5400
  4. v = 22.2 m/s (3 s.f.)
Q3Sound travels at 340 m/s in air. Calculate how long it takes thunder to travel 1.7 km.[3 marks]
  1. Convert: s = 1.7 km × 1000 = 1700 m
  2. Rearrange: t = s ÷ v
  3. t = 1700 ÷ 340
  4. t = 5.0 s

Frequently asked questions

What is the speed equation for GCSE Physics?

Distance travelled = speed × time, written s = vt. Distance is in metres (m), speed in metres per second (m/s) and time in seconds (s).

How do you convert km/h to m/s?

Divide by 3.6. For example, 72 km/h ÷ 3.6 = 20 m/s. To go from m/s to km/h, multiply by 3.6.

Why is s used for distance?

s is the standard symbol for distance or displacement on the GCSE equation sheet. You will see it in s = vt and again in v² − u² = 2as, so it is worth getting used to.

What is the difference between speed and velocity?

Speed is how fast something moves. Velocity is speed in a stated direction. Two cars at 20 m/s going opposite ways have the same speed but different velocities.