Enter any two values to solve for the third — speed, distance, or time
This speed calculator solves for speed, distance, or time when any two of the three values are known. It uses the fundamental relationship speed = distance / time. Whether you're planning a road trip, analyzing a race, or solving a physics problem, this tool computes the missing value and shows results in multiple common units.
A speed converter (or unit converter) changes a speed value from one unit to another (e.g., mph to km/h). This speed calculator solves for a missing variable — speed, distance, or time — using the formula s = d / t. You enter any two known values and it calculates the third automatically.
To convert km/h to m/s, divide by 3.6. To convert m/s to km/h, multiply by 3.6. For mph to km/h, multiply by 1.60934. For mph to m/s, multiply by 0.44704. This calculator handles all these conversions internally so you can input and read results in whichever unit is most convenient.