Precision Utility
Speed Distance Time
Calculator
Formula
S = D ÷ T
Modes
3 Solve Modes
Enter any two values and instantly calculate the third. Whether you need speed from distance and time, distance from speed and time, or time from speed and distance — this calculator handles it all with automatic unit conversion between km/h, mph, m/s, kilometres, miles and metres.
Calculated Speed
100.00 km/h
Speed
100.00 km/h
Distance
100 km
Time
1h 0m 0s
Formula Used
S = D ÷ T
How the speed distance time calculator works
Choose the value you want to find using the mode toggle: speed, distance or time. Then enter the two known values in the input fields. The calculator works out the missing value instantly as you type.
All calculations use the fundamental relationship between speed, distance and time. The calculator converts your inputs to base units (metres and seconds) internally, performs the calculation, then converts the result back to your chosen unit.
You can mix and match units freely. Enter distance in miles and get speed in km/h, or enter speed in m/s and distance in kilometres — the converter handles it all.
What you need to know about speed, distance and time
The speed-distance-time triangle is one of the most useful relationships in physics and everyday life. The three formulas are:
- Speed = Distance ÷ Time — how fast something is moving
- Distance = Speed × Time — how far something travels
- Time = Distance ÷ Speed — how long a journey takes
Common unit conversions to remember:
- 1 mile = 1.60934 kilometres
- 1 km/h = 0.27778 m/s
- 1 mph = 1.60934 km/h
- 60 mph = approximately 96.6 km/h
- 100 km/h = approximately 62.1 mph
These formulas assume constant (average) speed. In the real world, speed varies during a journey, so the values here represent average speed over the total distance and time.
Frequently asked questions
How do I calculate speed from distance and time?
Divide the distance travelled by the time taken. For example, if you drive 120 miles in 2 hours, your speed is 120 ÷ 2 = 60 mph. The formula is Speed = Distance ÷ Time.
How do I convert between mph and km/h?
To convert mph to km/h, multiply by 1.60934. To convert km/h to mph, divide by 1.60934. For example, 60 mph equals roughly 96.6 km/h.
What is the speed distance time triangle?
The speed distance time triangle is a memory aid. Distance sits on top, speed and time sit on the bottom. Cover the value you want to find: Speed = Distance ÷ Time, Distance = Speed × Time, Time = Distance ÷ Speed.
How do I calculate distance from speed and time?
Multiply speed by time. For example, travelling at 50 km/h for 3 hours gives 50 × 3 = 150 km. The formula is Distance = Speed × Time.
How do I calculate time from speed and distance?
Divide the distance by the speed. For example, a 200-mile journey at 40 mph takes 200 ÷ 40 = 5 hours. The formula is Time = Distance ÷ Speed.
What units does this calculator support?
The calculator supports kilometres, miles and metres for distance, and km/h, mph and m/s for speed. Time can be entered as hours, minutes and seconds. All conversions are handled automatically.