Enter any two of speed, distance, and time to calculate the third.

How to Use the Speed Calculator

Any two of speed, distance, and time — the same leave-one-blank pattern as the Density and Molarity calculators — solve for whichever's missing.

speed = distance ÷ time

This Speed Calculator solves for speed, distance, or time given the other two. Worth separating from velocity, which is a different (if related) idea: speed is just magnitude, no direction attached, while velocity tracks direction too. A car circling a track at a steady 60 mph has constant speed but constantly changing velocity — its direction never stops shifting even though its rate doesn't. This tool computes speed only.

Units need to actually match up — distance and time in units that pair sensibly (km with hours, miles with hours, meters with seconds). Mixing miles with seconds without converting first gives you a technically-computed number that doesn't correspond to any speed you'd recognize.