Race time calculator
Enter a recent race or time trial. You'll get the equivalent time and pace for every distance, your threshold pace, and even splits for the race you're targeting.
Your recent result
How the calculator works
It uses the Daniels–Gilbert equations, the model behind Jack Daniels' VDOT tables. Your result gives an estimate of your aerobic fitness, and the calculator finds the time at each other distance that the same fitness predicts.
The prediction assumes you have trained for the distance you're predicting. A 5K time says what your fitness could run for a marathon, not what your legs are ready for: without the long runs and weekly volume behind it, expect a real marathon to be slower than the table.
Getting the most accurate prediction
- Use a race or all-out time trial from the last 6 weeks, run on a flat course.
- Predict from the distance closest to your goal: a 10K predicts a half marathon better than a 5K does.
- A parkrun counts, as long as you raced it.
Heat, hills and trails
The equations are for flat roads in mild weather. Hot or humid days, hilly courses and trails all slow you down, so use the times as a guide for those races rather than a target.