Speed Calculator
Calculate speed from distance and time, distance from speed and time, or time from distance and speed. Supports multiple units.
hrs
Speed (km/h)
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Speed (mph) —
Speed (m/s) —
Distance (km) —
Time (hours) —
How to Use This Calculator
- Select what you want to solve for: Speed, Distance, or Time.
- Enter the two known values with their units.
- Results show the answer in multiple common units.
Formula
Speed = Distance ÷ Time
Distance = Speed × Time
Time = Distance ÷ Speed
Example
Example: 300 km in 3 hours → Speed = 100 km/h = 62.14 mph = 27.78 m/s.
Frequently Asked Questions
- Speed = Distance ÷ Time. For example, 100 miles in 2 hours = 50 mph.
- Time = Distance ÷ Speed. For example, 200 km at 80 km/h = 2.5 hours.
- Multiply mph by 1.60934. For example, 60 mph = 96.56 km/h.
- The speed of sound in air at 20°C is approximately 343 m/s, 1,235 km/h, or 767 mph.
- Average speed = Total distance ÷ Total time. If you travel at different speeds for different durations, this formula gives the overall average.