Turning a goal time into a number you can hold
Race goals are set in finish times but run in pace. A sub-2-hour half marathon sounds like a single target; on the road it is 5:41 per kilometre, held for 21.1 km. That translation is the difference between a plan and a wish.
The common benchmarks are worth knowing: a sub-4-hour marathon needs 5:41/km, a sub-25 5K needs 5:00/km, and a sub-50 10K needs 5:00/km as well. Enter any distance and goal time above and the calculator gives you the exact pace, in both km and miles.
Pace versus speed
Enter the distance you ran and your total time in hours, minutes, and seconds. The calculator shows your pace per kilometre or mile, the equivalent pace in the other unit, and your average speed. It works for a single run or for planning a target race pace.
Pace is the runner’s core number
Almost every running decision comes back to pace. It tells you whether a training run was easy or hard, lets you compare efforts across different distances, and turns a goal finish time into a concrete number to hold on race day. Because this tool also converts between per-km and per-mile pace, you can follow a training plan written in either unit without recalculating.
Planning a race
To hit a target time, work backwards: enter the race distance and your goal time to see the pace you need to average. Then compare that against your recent runs to judge whether the goal is realistic or needs adjusting. Remember that terrain, heat, and fatigue all affect real-world pace, so build in a little margin. All calculations run in your browser and nothing is stored.