Speed Distance Time Calculator
Calculate speed from distance and time, distance from speed and time, or time from speed and distance. Instantly convert between km/h, mph, m/s and more.
Speed
Distance
Time
Calculate Speed
Enter distance and time to find average speed
Enter the time taken to travel the above distance
Your Result
Calculated value with unit conversions
Choose what you want to calculate — Speed, Distance, or Time — enter the known values, then click Calculate to see your result.
Unit Conversions
Common conversions for speed, distance, and time units at a glance.
Speed Reference Guide
Typical speeds for common objects, vehicles and activities.
| Object / Activity | Speed (km/h) | Speed (mph) | Speed (m/s) |
|---|---|---|---|
| Walking (average adult) | 5 km/h | 3.1 mph | 1.4 m/s |
| Jogging | 8–12 km/h | 5–7.5 mph | 2.2–3.3 m/s |
| Running (recreational) | 12–16 km/h | 7.5–10 mph | 3.3–4.4 m/s |
| Cycling (leisure) | 15–25 km/h | 9–15 mph | 4.2–6.9 m/s |
| Car (urban road) | 50 km/h | 31 mph | 13.9 m/s |
| Car (motorway / highway) | 100–130 km/h | 62–81 mph | 27.8–36.1 m/s |
| Usain Bolt (100m world record) | 44.7 km/h | 27.8 mph | 12.4 m/s |
| Commercial aircraft | ~900 km/h | ~560 mph | ~250 m/s |
| Speed of sound (sea level) | 1,235 km/h | 767 mph | 343 m/s |
| Speed of light | 1.08 × 10⁹ km/h | 6.7 × 10⁸ mph | 3 × 10⁸ m/s |
Speed Distance Time FAQ
Answers to the most common questions about calculating speed, distance, and time.
Use the formula Speed = Distance ÷ Time. For example, if you travel 100 km in 2 hours, your average speed is 100 ÷ 2 = 50 km/h. Make sure your units are consistent — if distance is in km and time is in hours, the result is km/h. If distance is in metres and time is in seconds, the result is m/s.
Use the formula Distance = Speed × Time. For example, travelling at 60 km/h for 3 hours covers 60 × 3 = 180 km. Ensure units are compatible: km/h × hours = km; m/s × seconds = metres. If you need to mix units, convert first — e.g. convert 30 minutes to 0.5 hours before multiplying by a speed in km/h.
Use the formula Time = Distance ÷ Speed. For example, a 240 km journey at 80 km/h takes 240 ÷ 80 = 3 hours. The result is in the time unit consistent with your speed unit — km ÷ km/h gives hours; metres ÷ m/s gives seconds. To convert hours to hours and minutes, take the decimal part and multiply by 60.
The SDT triangle is a memory aid with Distance at the top, Speed and Time at the bottom. Cover the value you want to find: cover Distance → Speed × Time; cover Speed → Distance ÷ Time; cover Time → Distance ÷ Speed. If the two remaining values are side by side, multiply; if one is above the other, divide.
To convert km/h to mph, multiply by 0.621371. For example, 100 km/h × 0.621371 = 62.14 mph. To convert mph to km/h, multiply by 1.60934. For example, 60 mph × 1.60934 = 96.56 km/h. A quick mental shortcut: km/h ÷ 8 × 5 gives an approximate mph value.
Speed is a scalar quantity — it has magnitude only (e.g. 60 km/h). Velocity is a vector quantity — it has both magnitude and direction (e.g. 60 km/h heading north). In everyday driving or running calculations, speed is what you use. Velocity matters in physics when direction changes, such as circular or projectile motion. This calculator computes average speed over a given distance and time.
To convert m/s to km/h, multiply by 3.6. This is because 1 m/s = 1 metre per second = 3,600 metres per hour = 3.6 km/h. For example, 10 m/s × 3.6 = 36 km/h. To convert km/h to m/s, divide by 3.6 (or multiply by 0.2778). For example, 90 km/h ÷ 3.6 = 25 m/s.
Average speed is total distance divided by total time, regardless of variations during the journey. Instantaneous speed is the speed at any given moment (like a speedometer reading). This calculator computes average speed. For example, a 100 km drive taking 1.5 hours gives an average speed of 66.7 km/h, even if you stopped briefly or varied your speed throughout.