Running
Mile Time Calculator
Updated 1 Nov 2026 · Source: NIST unit conversion factors ↗
Enter a recent race result to estimate how fast you could run one mile all out. The tool works from a 1,500 m, 5K, 10K or half marathon time.
Worked example
- Riegel: 27:00 × (1,609 ÷ 5,000)^1.06 = 8:07
Mile time predicted from a 5K
| 5K time | Mile | Pace per mile in the 5K |
|---|---|---|
| 18:00 | 5:25 | 5:48 |
| 20:00 | 6:01 | 6:26 |
| 22:00 | 6:37 | 7:05 |
| 24:00 | 7:13 | 7:43 |
| 26:00 | 7:49 | 8:22 |
| 28:00 | 8:25 | 9:01 |
| 30:00 | 9:01 | 9:39 |
| 32:00 | 9:37 | 10:18 |
| 34:00 | 10:13 | 10:57 |
| 36:00 | 10:50 | 11:35 |
| 38:00 | 11:26 | 12:14 |
| 40:00 | 12:02 | 12:52 |
| 42:00 | 12:38 | 13:31 |
| 44:00 | 13:14 | 14:10 |
| 46:00 | 13:50 | 14:48 |
| 48:00 | 14:26 | 15:27 |
How the prediction works
The tool uses the Riegel formula: predicted time equals known time times (new distance divided by known distance) raised to the power 1.06. That exponent of 1.06, as commonly used, is based on Peter Riegel's work from 1977 and 1981. It makes each step up in distance a bit slower per mile and each step down a bit faster.
From a 27:00 5K the formula predicts an 8:07 mile, while the pace in that 5K was 8:41 per mile. So the mile comes out about 34 seconds faster than 5K pace.
Why a 5K is the best input
The closer the known race is to a mile, the better the guess. A 1,500 m or 5K result is a fair match. A half marathon is more than 13 times as long, and speed and endurance do not always line up in the same runner. The 5K pace chart helps if you need your pace from a 5K time.
Where the estimate falls short
The formula assumes you are equally trained for both distances. A runner who only does long, easy runs may lack the leg speed for the predicted mile. Treat the result as a target to test, not a promise.
Weather, track or road, and how hard you push also move the number. Riegel described the relation for efforts of roughly 3.5 to 230 minutes, and a mile sits near the short end of that range. The method page lists the formulas we use.
Testing your mile on a track
For a real number, run a mile on a 400 m track. Four laps is 1,600 m, about 9 m short of a mile, so carry on a few steps past the line.
Warm up first, start a touch slower than the predicted pace, and run the last lap hardest. If you beat the estimate, your speed is ahead of your endurance. If you fall short, it is the other way around.
Related pages
Race Time Predictor, Km to Mile Pace, 10K Pace Chart, How Far Is a 5K?
Questions
What is a good mile time?
There is no solid national data set on mile times for adults, so we do not give an average. Compare the result with your own past miles, or set a target from your 5K here.
Can I predict a 5K from my mile?
Yes, the same formula works in either direction. The race time predictor takes a mile as its input.
What does a 30:00 5K predict for the mile?
About 9:01, compared with 9:39 per mile in the 5K itself.
How we calculate: every formula, with its author and year, is on our method page; data sources and their licenses are on sources.
gymnical.com gives estimates from published formulas and public data. It is not medical advice and not a training prescription. Last reviewed November 2026.