How to use the pace calculator
- Choose whether you want to find your pace (from a finish time) or your finish time (from a target pace).
- Pick a race distance, or choose Other distance and enter it in kilometers or miles.
- Enter your time in hours, minutes and seconds — or your pace in minutes and seconds per mile or kilometer.
- See your pace, speed and predicted times for other race distances.
Pace formulas
Example: a 4-hour marathon (42.195 km, 26.2 miles) is 240 minutes ÷ 26.22 miles = 9:09 per mile, or 240 ÷ 42.195 = 5:41 per km.
Common race paces
| Goal | Pace per mile | Pace per km |
|---|---|---|
| Sub-20 5K | 6:26 | 4:00 |
| Sub-25 5K | 8:03 | 5:00 |
| Sub-30 5K | 9:39 | 6:00 |
| Sub-50 10K | 8:03 | 5:00 |
| Sub-2 half marathon | 9:09 | 5:41 |
| Sub-4 marathon | 9:09 | 5:41 |
| Sub-3 marathon | 6:52 | 4:16 |
How race time prediction works
Runners slow down as distance increases. The Riegel formula models this with T₂ = T₁ × (D₂ ÷ D₁)1.06. For example, a 25-minute 5K predicts about a 52-minute 10K and a 1:55 half marathon. Predictions are most accurate between similar distances and assume you have trained for the longer race — marathon predictions from short races are often optimistic.
Tips for pacing a race
- Start slower than goal pace for the first mile or kilometer; going out too fast is the most common mistake.
- Aim for even or slightly negative splits (a faster second half).
- Do most training runs at an easy, conversational pace — often 1–2 minutes per mile slower than race pace.
Frequently asked questions
How do I calculate my running pace?
Divide your time by the distance. If you run 5 km in 25 minutes, your pace is 25 ÷ 5 = 5 minutes per km, which is about 8:03 per mile.
What pace do I need for a 4-hour marathon?
About 9:09 per mile or 5:41 per kilometer, held for the full 26.2 miles (42.195 km).
What is a good pace for a beginner?
Many beginners run between 10 and 13 minutes per mile (6:15 to 8:05 per km). The right pace is one where you can still speak in short sentences.
How do I convert pace per km to pace per mile?
Multiply the pace per kilometer by 1.609. A 6:00 per km pace is 6 × 1.609 = 9.66 minutes, or about 9:39 per mile.
How accurate are race time predictions?
They are a reasonable guide when you have trained for the target distance. Hills, heat, wind, fatigue and pacing on race day can easily change the result by several minutes.
This calculator provides general information only and is not a substitute for professional medical advice, diagnosis or treatment. Always consult a doctor or other qualified health provider about your individual situation.
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