Math
Speed, Distance & Time Calculator
Calculate speed, distance, or time using the speed distance time formula. Choose what you want to find, enter the other two values, and get an instant result with unit conversion and a running pace calculator.
Speed Distance Time Formulas
SpeedSpeed = Distance ÷ Time
DistanceDistance = Speed × Time
TimeTime = Distance ÷ Speed
Speed Reference Table
| Object / Activity | km/h | mph |
|---|---|---|
| Human walking | 5 | 3.1 |
| Casual cycling | 15 | 9.3 |
| Sprinting (elite) | 44.7 | 27.8 |
| City speed limit | 50 | 31.1 |
| Highway speed limit | 100 | 62.1 |
| Commercial airplane | 900 | 559 |
| Speed of sound | 1235 | 767 |
| Speed of light | 1,079,252,848 | 670,616,629 |
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Frequently Asked Questions
What is the speed distance time formula?
The three related formulas are: Speed = Distance ÷ Time, Distance = Speed × Time, Time = Distance ÷ Speed. Example: A car travels 240 km in 3 hours → Speed = 240 ÷ 3 = 80 km/h. At 80 km/h for 2.5 hours → Distance = 80 × 2.5 = 200 km. To travel 150 km at 60 km/h → Time = 150 ÷ 60 = 2.5 hours (2h 30min).
How do I convert km/h to mph?
Multiply km/h by 0.62137 to get mph. Examples: 100 km/h = 62.1 mph, 120 km/h = 74.6 mph, 50 km/h = 31.1 mph. Quick mental trick: multiply by 0.6 for a rough estimate — 100 × 0.6 = 60 mph (actual 62.1 mph).
How do I convert mph to km/h?
Multiply mph by 1.60934 to get km/h. Examples: 60 mph = 96.6 km/h, 70 mph = 112.7 km/h, 100 mph = 160.9 km/h. Mental trick: multiply mph by 1.6 — 60 × 1.6 = 96 km/h (actual 96.6 km/h).
What is average speed and how is it calculated?
Average speed = Total Distance ÷ Total Time. Example: driving 60 km/h for 1 hour then 120 km/h for 1 hour. Total distance = 180 km. Total time = 2 hours. Average speed = 90 km/h. Important: when the time periods differ, you cannot simply average the speeds. Always use total distance ÷ total time.
What is running pace and how do I calculate it?
Running pace = 60 ÷ Speed (km/h), expressed as minutes per kilometer. At 10 km/h → 6:00 min/km. At 8 km/h → 7:30 min/km. At 12 km/h → 5:00 min/km. Marathon finish times by pace: sub-3 hours needs 4:16/km, 4 hours needs 5:41/km, 5 hours needs 7:06/km. The speed calculator above shows your running pace automatically.
How long does it take to drive 100 miles?
At 60 mph: 100 ÷ 60 = 1h 40min. At 70 mph: 100 ÷ 70 = 1h 26min. At 55 mph: 100 ÷ 55 = 1h 49min. Convert to km first: 100 miles = 160.9 km. Use the 'Find Time' mode above with your speed for precise results.
What is the speed of sound in km/h and mph?
The speed of sound in dry air at 20°C is approximately 343 m/s = 1,235 km/h = 767 mph. This is called Mach 1. It varies with temperature — faster in warmer air (about 0.6 m/s per °C increase). Sound travels much faster through water (1,480 m/s) and steel (5,100 m/s) because these denser media transmit vibrations more efficiently.