Speed, Distance & Time Calculator
By Santaji GadepatilinUpdated October 27, 2026
Speed is distance divided by time. This simple relationship answers everyday questions — how long a journey takes, how fast you need to go or how far you will travel. This free speed, distance & time calculator solves for whichever value you leave blank and shows the formula and steps.
Time (h) vs Speed (km/h) — other inputs held at your current values.
How to use the speed, distance & time calculator
Enter any two of distance, speed and time — the third is calculated. Each field has its own unit, so you can mix kilometres with mph or minutes with hours.
Speed, distance & time formula
distance = speed × time speed = distance ÷ time time = distance ÷ speed
Worked examples
- Travel time: 150 km at 60 km/h → 150 ÷ 60 = 2.5 h (2 h 30 min).
- Average speed: 42.195 km marathon in 3 h 30 min → 42.195 ÷ 3.5 = 12.06 km/h.
- Distance: walking at 5 km/h for 45 minutes → 5 × 0.75 = 3.75 km.
Converting decimal hours
0.5 h = 30 min · 0.25 h = 15 min · 0.1 h = 6 min. Switch the Time unit to minutes to avoid conversions.
Journey time table
| Distance | At 40 km/h | At 60 km/h | At 80 km/h | At 100 km/h |
|---|---|---|---|---|
| 10 km | 0 h 15 min | 0 h 10 min | 0 h 08 min | 0 h 06 min |
| 25 km | 0 h 38 min | 0 h 25 min | 0 h 19 min | 0 h 15 min |
| 50 km | 1 h 15 min | 0 h 50 min | 0 h 38 min | 0 h 30 min |
| 100 km | 2 h 30 min | 1 h 40 min | 1 h 15 min | 1 h 00 min |
| 200 km | 5 h 00 min | 3 h 20 min | 2 h 30 min | 2 h 00 min |
| 500 km | 12 h 30 min | 8 h 20 min | 6 h 15 min | 5 h 00 min |
Average speed over several legs
Average speed is total distance ÷ total time, not the average of the speeds. Driving 60 km at 60 km/h (1 h) and 60 km at 120 km/h (0.5 h) gives 120 km in 1.5 h — an average of 80 km/h, not 90.
Relative speed
- Moving in the same direction: subtract speeds. A car at 100 km/h overtaking a truck at 80 km/h closes at 20 km/h.
- Moving towards each other: add speeds. Two trains 300 km apart at 80 and 70 km/h meet after 300 ÷ 150 = 2 hours.
Pace
Runners and walkers often use pace (minutes per km), which is the inverse of speed. 12 km/h = 5 min/km. See the pace calculator.
Keep units consistent
The most common mistake is mixing units by hand, such as metres with km/h. The calculator converts every field automatically — just pick the unit you have.
Frequently asked questions
What is the formula for speed?
Speed = distance ÷ time. Distance = speed × time, and time = distance ÷ speed.
How long does 150 km take at 60 km/h?
150 ÷ 60 = 2.5 hours, which is 2 hours 30 minutes.
What is average speed?
Total distance divided by total time, including stops. It is usually lower than your cruising speed.
How long does it take to travel 150 km at 60 km/h?
2.5 hours, or 2 hours 30 minutes.
How do I find speed from distance and time?
Speed = distance ÷ time. 120 km in 1.5 hours is 80 km/h.