Speed Distance Time
Enter any two values — speed, distance or time — and the third is calculated instantly.
How to use the speed distance time triangle
Cover the value you want to find in the triangle. What remains shows the formula: cover D → S×T. Cover S → D÷T. Cover T → D÷S.
Frequently asked questions
How do I convert km/h to m/s?
Divide by 3.6. So 90 km/h = 90 ÷ 3.6 = 25 m/s. To convert m/s to km/h, multiply by 3.6. This is because 1 km = 1000 m and 1 hour = 3600 seconds.
What is the speed of light in km/h?
About 1,079,252,848 km/h (roughly 1.08 billion km/h). In m/s it is 299,792,458 m/s exactly. This calculator is designed for everyday speeds — at relativistic speeds, classical mechanics do not apply.
How do I calculate how long a trip will take?
Divide the distance by your average speed. A 400 km trip at an average speed of 80 km/h takes 400 ÷ 80 = 5 hours. Remember to account for stops, traffic and speed limit changes.
What is the difference between speed and velocity?
Speed is a scalar (magnitude only). Velocity is a vector (magnitude + direction). At 60 km/h northwards, the speed is 60 km/h and the velocity is 60 km/h north. This calculator works with speed only.
How many kilometres per hour is 100 mph?
100 mph = 160.934 km/h. The conversion factor is 1 mile = 1.60934 km. Indian roads use km/h, while the US and UK use mph. Highway speed limits in India are typically 80–120 km/h.