Speed Distance Time Calculator

The Speed, Distance and Time Calculator solves all three variables of the fundamental motion equation: Speed equals Distance divided by Time. Enter any two of the three values to instantly calculate the third. This tool is essential for road trip planning, athletic training, physics problems, logistics calculations, aviation, maritime navigation and any situation where you need to find speed, estimate arrival time or plan a journey based on distance.

The basic formula triangle is: Speed = Distance / Time; Distance = Speed x Time; Time = Distance / Speed. Converting between speed units is also frequently needed: 1 km/h equals 0.621 mph; 1 mph equals 1.609 km/h; 1 knot (nautical mile per hour) equals 1.852 km/h or 1.151 mph. A car travelling at 100 km/h (62 mph) covers 100 kilometres in exactly 1 hour, 200 kilometres in 2 hours, or reaches a destination 250 kilometres away in 2 hours and 30 minutes. At 120 km/h on a motorway, the same 250 km journey takes 2 hours and 5 minutes — a 25-minute saving.

For athletics: a 5 km race in 25 minutes represents an average speed of 12 km/h or a pace of 5 minutes per kilometre. A marathon (42.195 km) run at the world record pace of 2 hours 0 minutes 35 seconds averages 20.97 km/h. For fuel cost estimation alongside speed, use our Fuel Cost Calculator. For unit conversions, use our Unit Converter. Free, no registration required.