Speed Calculator: Speed, Distance, and Time
The speed-distance-time relationship is fundamental to travel planning, physics, and athletics. Our calculator solves for any of the three values when you provide the other two. Choose your calculation mode, enter known values, and get instant results with automatic unit conversions.
For unit conversions, see our Unit Converter. For area calculations, try Area Calculator.
Speed-Distance-Time Formula
Speed = Distance ÷ Time. If you travel 100 km in 2 hours, your speed is 50 km/h. Distance = Speed × Time. At 60 mph for 3 hours, you travel 180 miles. Time = Distance ÷ Speed. 150 km at 75 km/h takes 2 hours.
Speed Unit Conversions
1 km/h = 0.621 mph = 0.278 m/s. 1 mph = 1.609 km/h. 1 knot = 1.852 km/h (used in maritime/aviation).