# What is my VDOT?

Computes a runner’s VDOT from one race distance and time with the Daniels and Gilbert equations, with equal-effort times for 1,500 m to the marathon and the pace at VO2max.

- Page: https://www.acalculator.org/sports/vdot-calculator
- JSON spec: https://www.acalculator.org/sports/vdot-calculator.json
- Version: 300f590b1833

## Default answer

Example with the default inputs (Race distance 3.10685596118667 mi, Race time 20 min): 3.107 mi in 20 min is a VDOT of 49.8.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| d | Race distance | The distance of a recent race run at full effort. A marathon is 42.195 km. |
| t | Race time | The finishing time of that race. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| vdot | VDOT | Oxygen cost of the race speed ÷ the share of VO2max held for the race time. |
| vo2 | Oxygen cost of the race pace | VO2 at the race speed, in mL of oxygen per kg per minute. |
| share | Share of VO2max held | The share of VO2max a runner can hold for the race time, by the Daniels and Gilbert formula. |
| r1500 | 1,500 m time | The 1,500 m time at the same VDOT, to the second. |
| rMile | 1 mile time | The 1 mile time at the same VDOT, to the second. |
| r5k | 5 km time | The 5 km time at the same VDOT, to the second. |
| r10k | 10 km time | The 10 km time at the same VDOT, to the second. |
| rHalf | Half marathon time | The half marathon time at the same VDOT, to the second. |
| rMarathon | Marathon time | The marathon time at the same VDOT, to the second. |
| paceKm | Pace at VO2max, per km | The speed whose oxygen cost equals the VDOT, as time per kilometre. |
| paceMile | Pace at VO2max, per mile | The same speed as time per mile. |

## Method

v = distance ÷ time (m/min); VO2 = −4.60 + 0.182258 v + 0.000104 v²; %max = 0.8 + 0.1894393 e^(−0.012778 t) + 0.2989558 e^(−0.1932605 t), t in minutes; VDOT = VO2 ÷ %max.

## Assumptions

- The race was run at full effort on a flat course in good conditions.
- Equal-VDOT times assume the runner is as well trained for the other distance.
- VDOT is a performance score, not a measured VO2max from a lab test.

## Worked examples

1. d = 5,000, t = 1,200 gives vdot = 49.806233, vo2 = 47.4645, r10k = 41:28, rHalf = 1:31:50, rMarathon = 3:11:17, paceKm = 3:51, paceMile = 6:11. Source: Daniels J, Gilbert J. Oxygen Power: Performance Tables for Distance Runners, 1979 (equations as given in Daniels’ Running Formula); equations written out at https://dev.to/keepknow/how-race-time-predictors-actually-work-daniels-vdot-vs-riegel-with-the-javascript-55k1 (retrieved 2026-10-01).
2. d = 42,195, t = 12,600 gives vdot = 44.553531, r5k = 22:00, r10k = 45:37. Source: Daniels and Gilbert 1979, Oxygen Power (VO2 and %VO2max equations).
3. d = 5,000, t = 1,196 gives vdot = 50. Source: Daniels and Gilbert 1979, Oxygen Power.

## FAQ

### What is VDOT?

A running fitness score from Jack Daniels and Jimmy Gilbert. It is the VO2max that would explain your race time, if you ran with average running economy. Higher is fitter: a 20:00 5 km gives a VDOT of about 49.8.

### How is VDOT calculated?

From two equations. The oxygen cost of the race speed v (metres per minute) is −4.60 + 0.182258 v + 0.000104 v². The share of VO2max you can hold for t minutes is 0.8 + 0.1894393 e^(−0.012778 t) + 0.2989558 e^(−0.1932605 t). VDOT is the first divided by the second.

### How does the calculator predict my other race times?

For each distance it finds the time that gives the same VDOT. From a 20:00 5 km that is 41:28 for 10 km, 1:31:50 for the half marathon and 3:11:17 for the marathon.

### Is VDOT the same as VO2max?

No. VO2max is measured in a lab. VDOT is worked out from a race, so it also reflects running economy and race skill. Two runners with the same VO2max can have different VDOTs.

### Why does my marathon prediction feel too fast?

The prediction assumes you are as well trained for the marathon as for the race you typed. Without long runs and marathon-specific training, most runners are slower than a 5 km time predicts.

### Why are the times a second or two off Daniels’ tables?

The book’s tables were rounded when they were printed; the calculator solves the equations to the second. At VDOT 50 the equations give 19:56 for 5 km, and the table lists 19:57.

## Sources

- Daniels J, Gilbert J. Oxygen Power: Performance Tables for Distance Runners. Tempe, AZ, 1979; the equations and VDOT tables are used in Daniels J. Daniels’ Running Formula, 4th edition, Human Kinetics, 2021, retrieved 2026-10-01. https://us.humankinetics.com/products/daniels-running-formula-4th-edition
- The VO2 and %VO2max equations written out with their constants: How race time predictors actually work, Daniels VDOT vs Riegel, DEV Community, retrieved 2026-10-01. https://dev.to/keepknow/how-race-time-predictors-actually-work-daniels-vdot-vs-riegel-with-the-javascript-55k1