What does this tool do?
The Running Pace Calculator turns a distance and time into your pace per kilometre or mile, your average speed and predicted finish times for 5K, 10K, half marathon and marathon at that same pace. It is built for runners planning training or setting a race goal.
How to use it
- Enter your values into the fields.
- The result is calculated instantly.
- Read or copy the result.
Pace, speed and race predictions from one input
Enter a distance and the time you ran it in, and the tool instantly returns three things: pace per unit (for example 5:00 /km), average speed in km per hour, and finish times for 5K, 10K, half marathon and marathon at that pace. Because the race predictions scale your pace directly, you can quickly see whether a training run matches your target race pace. Switch between km and miles with a single tap and the distances and results update automatically.
Dialling in your goal race pace
If you have a target race time, enter that distance and time to read the pace you need to hold in training. For example, a 50-minute 10K calls for 5:00 /km, so you can set your tempo runs accordingly. Conversely, enter a training run's time to see how long a marathon would take at that pace and judge whether your goal is realistic. Predictions assume an even pace; in real races, fatigue can slow you over longer distances.
Frequently asked questions
What is the difference between pace and speed?
Pace is the time to cover one unit of distance (minutes per km or mile), where lower is faster. Speed is the distance covered per unit of time (km per hour), where higher is faster. The calculator shows both at once.
How accurate are the race time predictions?
The predictions apply your entered pace directly to each distance, meaning they assume a constant speed. They are quite accurate between shorter distances, but over long distances like the marathon the real time is usually a bit slower because holding pace to the finish is hard.
How should I enter the time?
Enter the time as hours, minutes and seconds in three separate fields. For example, if you ran 10 km in 50 minutes, put 0 for hours, 50 for minutes and 0 for seconds, and the tool calculates a pace of 5:00 /km.
Is Running Pace Calculator free?
Yes. Running Pace Calculator and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Running Pace Calculator works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.