Running Pace Calculator
Enter any two of distance, time, and pace, and the remaining value is calculated automatically. Shows pace per km and speed (km/h) together, plus predicted times for popular race distances.
(min:sec/km)
(km/h)
(h:m:s)
(km)
| Distance | Predicted Time | Pace |
|---|---|---|
| 5K | -- | -- |
| 10K | -- | -- |
| Half Marathon (21.0975km) | -- | -- |
| Full Marathon (42.195km) | -- | -- |
Predicted finish time for each distance at your current pace (approximate, assuming an even pace).
How to Use
Choose what to calculate
Select Pace, Time, or Distance using the tabs. The chosen value is calculated automatically, and the other two become input fields.
Enter the other two values
Enter two of distance (km), time (h:m:s), and pace (min:sec/km), excluding the one you want to calculate. Preset buttons let you fill 5K, 10K, half, or full distance with one tap.
Check results and predicted times
Pace, speed (km/h), time, and distance appear instantly, along with predicted times for 5K, 10K, half, and full marathon.
Copy and use
Use the "Copy Results" button to copy everything at once for your training log or to share on social media.
About the Running Pace Calculator
The Running Pace Calculator uses the relationship between distance, time, and pace to instantly derive the third value from any two. Pace is expressed as minutes and seconds per km and is automatically converted to speed (km/h). It is ideal for planning the pace required for goals such as a sub-4-hour or sub-3:30 marathon. All calculations run entirely in your browser, and your inputs are never sent to a server.
Features
- Three-way calculationEnter any two of distance, time, and pace to instantly compute the third.
- Speed (km/h) shown tooIn addition to min:sec/km pace, speed (km/h) is shown at the same time, handy for treadmill settings.
- Predicted race timesSee predicted finish times for 5K, 10K, half, and full marathon at a glance.
- Privacy protectedAll processing happens in your browser. Your inputs are never sent to servers.
Use Cases
- Plan the pace needed for a goal time (sub-4, sub-3:30, etc.)
- Check pace for easy runs or intervals
- Set treadmill speed (km/h)
- Build a marathon or half-marathon race plan
- Predict 5K and 10K times
FAQ
What is running pace?
How do I convert pace to speed (km/h)?
What are the half and full marathon distances?
What pace is needed for a sub-4-hour marathon?
Is my data saved or sent anywhere?
Feedback
Missing a feature, or getting a result that looks wrong? Let us know — we improve our tools based on your feedback.