Running
VDOT calculator.
Enter a recent race distance and time to get your VDOT running score, and the equivalent times for 1500 m up to the marathon. Uses the published Daniels and Gilbert equations. Runs in your browser.
Race result
VDOT
Fill the form and press Calculate.
Worked example
A 5 km in 20:00 is 250 m per minute. Oxygen cost = −4.60 + 0.182258 × 250 + 0.000104 × 250² = 47.46 ml/kg/min. For 20 minutes, the sustainable fraction is 0.8 + 0.1894393 × e−0.012778×20 + 0.2989558 × e−0.1932605×20 = 0.9530. VDOT = 47.46 / 0.9530 = 49.8. The same fitness predicts about 41:28 for 10 km, 1:31:50 for the half marathon and 3:11:17 for the marathon.
How it works
Jack Daniels and Jimmie Gilbert modelled running performance with two equations. Oxygen cost: VO2 = −4.60 + 0.182258 v + 0.000104 v², where v is speed in metres per minute. Fraction of VO2 max you can sustain: 0.8 + 0.1894393 e−0.012778 t + 0.2989558 e−0.1932605 t, where t is race time in minutes. VDOT = oxygen cost / sustainable fraction. Equivalent times come from solving the same equations for the time that gives the same VDOT at another distance.
What VDOT is not. It is a performance score, “V-dot-O2 max” as if you were equally trained at every distance, not a lab-measured VO2 max. Predictions assume similar training for each distance, so a marathon prediction from a 5 km time is optimistic if you lack the long-run mileage. The equations suit races from about 3.5 minutes up to a few hours. Published Daniels tables round times, so results can differ by a few seconds at shorter distances and up to about 10 seconds at the marathon.
Sources and basis (checked 2026-10-05): VDOT equations and quick-reference chart (VDOT 50: 5 km 19:56, 10 km 41:20, half 1:31:31, marathon 3:10:40; reproduced by this tool); Daniels, J. (2014). Daniels’ Running Formula. Human Kinetics; Daniels, J. and Gilbert, J. (1979). Oxygen Power: Performance Tables for Distance Runners.
FAQ
What is VDOT?
A running performance score created by Jack Daniels and Jimmie Gilbert. It converts a race result into one number, and the same number gives equivalent times at other distances.
How do you calculate VDOT from a 5K time?
Work out your speed in metres per minute, compute oxygen cost with the Daniels quadratic, then divide by the fraction of VO2 max sustainable for your race time. This calculator does it for you.
Is VDOT the same as VO2 max?
No. VDOT is calculated from performance, so it also reflects running economy and training. It is not a lab VO2 max.
Are the equivalent race times accurate?
They are reliable when you are equally trained for each distance. Marathon predictions from short races tend to be optimistic without long runs.
What is a good VDOT?
There is no single good number. Use it to track your own fitness and to compare equivalent race results over time.
Disclaimer
Not medical advice. Predictions are estimates. Build mileage gradually, and check with a healthcare professional before starting hard training if you have a health condition.