Speed, Distance, Time Calculator

1. Select what to solve for. Choose speed, distance, or time. The field you are solving for grays out. Only enter values in the active fields.
2. Choose your units. Speed can be in mph, km/h, m/s, ft/s, or knots. Distance can be in miles, kilometers, meters, feet, or nautical miles. Time uses hours, minutes, and seconds. The calculator handles all conversions internally.
3. Enter the two known values. For time, fill in hours, minutes, and seconds as needed. For speed and distance, enter the number and select the unit from the dropdown.
4. Read the results. The primary result shows in your selected unit. For solved speed, a conversion panel shows all speed units at once.

Example: a runner completes 5 miles in 42 minutes 30 seconds. Set "solve for speed," enter 5 miles and 0 hours / 42 minutes / 30 seconds. Speed = 5 miles / 0.708 hours = 7.07 mph.

Speed    = Distance / Time
Distance = Speed x Time
Time     = Distance / Speed

Common speed conversions:

Reference speeds: walking pace 3-4 mph (4.8-6.4 km/h), highway driving 65-75 mph, commercial airplane 575 mph (925 km/h), speed of sound 767 mph (1,235 km/h) at sea level, speed of light 670,616,629 mph.