Speed Calculator
All fields update instantly as you type — no button needed.
Speed Unit Converter
Enter a speed value and pick a unit to see all conversions instantly.
Pace Calculator for Runners
Convert between running pace and speed. Useful for training plans.
Speed → Pace
Pace → Speed
Real-World Speed Reference
| Object / Activity | km/h | mph | m/s |
|---|---|---|---|
| 🐌 Snail | 0.05 | 0.03 | 0.014 |
| 🚶 Human Walk | 5 | 3.11 | 1.39 |
| 🚴 Cycling | 25 | 15.53 | 6.94 |
| 🏃 Human Sprint | 37 | 22.99 | 10.28 |
| 🚗 Car (Highway) | 120 | 74.56 | 33.33 |
| 🐆 Cheetah | 120 | 74.56 | 33.33 |
| 🚄 High-Speed Train | 320 | 198.84 | 88.89 |
| ✈️ Commercial Jet | 900 | 559.23 | 250.0 |
| 🔊 Speed of Sound | 1,235 | 767.27 | 343.0 |
| 🚀 Orbital Rocket | 28,000 | 17,398 | 7,778 |
| 💡 Speed of Light | 1,079,252,848 | 670,616,629 | 299,792,458 |
Speed, Distance, and Time — The SDT Triangle
Speed, distance, and time are three fundamental quantities linked by a simple relationship. The SDT triangle (also called the magic triangle) is a visual memory aid that shows how these three quantities relate to one another.
Cover the quantity you want to find and the remaining two show the operation: cover D and you see S × T; cover S and you see D ÷ T; cover T and you see D ÷ S.
The Three Formulas
| Finding | Formula | Example |
|---|---|---|
| Speed | Speed = Distance ÷ Time | 150 km ÷ 3 h = 50 km/h |
| Distance | Distance = Speed × Time | 80 km/h × 2.5 h = 200 km |
| Time | Time = Distance ÷ Speed | 300 km ÷ 60 km/h = 5 h |
Speed Unit Conversion Reference
The table below shows conversion factors between the five most common speed units.
| Unit | km/h | mph | m/s | knots | ft/s |
|---|---|---|---|---|---|
| 1 km/h | 1 | 0.6214 | 0.2778 | 0.5400 | 0.9113 |
| 1 mph | 1.6093 | 1 | 0.4470 | 0.8690 | 1.4667 |
| 1 m/s | 3.6000 | 2.2369 | 1 | 1.9438 | 3.2808 |
| 1 knot | 1.8520 | 1.1508 | 0.5144 | 1 | 1.6878 |
| 1 ft/s | 1.0973 | 0.6818 | 0.3048 | 0.5925 | 1 |
Pace vs. Speed for Runners
Runners often use pace rather than speed. Pace is the time required to cover one unit of distance — the inverse of speed.
- Pace (min/km) = 60 ÷ Speed (km/h)
- Pace (min/mile) = 60 ÷ Speed (mph)
- Speed (km/h) = 60 ÷ Pace (min/km)
For example, a 10 km/h running speed equals a 6:00 min/km pace. A marathon runner finishing in 4 hours covers 42.195 km at 10.55 km/h — a pace of approximately 5:41 min/km.
| Speed (km/h) | Pace (min/km) | Pace (min/mile) | Runner Level |
|---|---|---|---|
| 7 km/h | 8:34 min/km | 13:47 min/mi | Beginner / Walk-jog |
| 10 km/h | 6:00 min/km | 9:39 min/mi | Recreational runner |
| 12 km/h | 5:00 min/km | 8:03 min/mi | Moderate runner |
| 15 km/h | 4:00 min/km | 6:26 min/mi | Advanced runner |
| 20 km/h | 3:00 min/km | 4:50 min/mi | Elite distance runner |
Frequently Asked Questions
What is average speed?
Average speed is the total distance traveled divided by the total time taken. It does not account for direction. For example, traveling 150 km in 3 hours gives an average speed of 50 km/h. Note that average speed differs from average velocity, which is a vector quantity that includes direction.
What is the formula for speed?
Speed = Distance ÷ Time. The three related forms are: Speed = Distance / Time, Distance = Speed × Time, and Time = Distance / Speed. Rearranging any one gives the other two — this is the core of the SDT triangle.
How do I convert mph to km/h?
Multiply by 1.60934. For example, 60 mph × 1.60934 = 96.56 km/h. To go the other way (km/h to mph), multiply by 0.62137. A quick mental shortcut: divide by 5 then multiply by 8 (or multiply by 1.6).
What is pace in running?
Pace is the time it takes to cover one unit of distance, expressed in min/km or min/mile. It is the inverse of speed. A speed of 10 km/h equals a pace of 6:00 min/km. Runners prefer pace because it directly tells them how long each kilometre or mile will take during a race or training run.
How fast is the speed of sound?
The speed of sound in dry air at 20°C is approximately 343 m/s — about 1,235 km/h or 767 mph. At sea level at 0°C it drops to 331 m/s. Sound travels significantly faster in denser media: approximately 1,480 m/s in water and about 5,100 m/s in steel.