What This Calculator Does

The Running Pace Calculator solves time, distance or pace from the other two. It supports kilometres and miles, shows both pace units and average km/h, and includes 5K, 10K, half-marathon and marathon distance buttons. A table gives constant-pace splits, including the final partial unit.

When to Use It

Use it to check a run, convert a finish-time target to pace or calculate distance at a fixed pace. The model does not predict fitness, race performance or training safety. For other speed units see the speed converter.

Inputs Explained

Choose the value to solve and fill the other two. Time accepts M:SS or H:MM:SS; 25:00 means 25 minutes. Pace accepts M:SS per selected distance unit. Hours and minutes must be non-negative integers; seconds may include a decimal but must be below 60. Minutes in three-part time must also be below 60. Time and distance must be positive.

Enter distance from your measurement or run record, without assuming that a device display guarantees course accuracy. Pace conversion changes time per length unit while preserving total elapsed time. Whether stops are included depends on the elapsed-time record you enter; the calculator does not deduct pauses.

A partial final unit remains in the table. For 2.5 km at five minutes per kilometre, two splits take five minutes each and the final half kilometre takes two minutes thirty seconds, for 12:30 total. The distance column is cumulative, while split time describes only that segment.

How the Calculation Works

Pace = time/distance; time = distance×pace; distance = time/pace. One mile is 1.609344 km, so seconds per mile = seconds per kilometre×1.609344. Speed in km/h = kilometres/seconds×3600. Every split uses that same unrounded pace; a final partial unit takes its proportional time.