VDOT is a performance-based running fitness score introduced by exercise physiologist Jack Daniels. It correlates closely with VO2 max but is derived directly from race times rather than lab testing. A higher VDOT indicates better aerobic capacity and race potential.

How accurate is this estimate?

VDOT is accurate when the input race was run at genuine maximum effort on a flat course in neutral conditions. Hilly courses, heat, or wind will skew the result. For best accuracy, use a race between 1500 m and the marathon distance run at full effort.

What are the five training zones?

Easy (E): comfortable aerobic base — typically 60–79% VO2 max. Marathon (M): goal race pace. Threshold/Tempo (T): comfortably hard — ~88% VO2 max, improving lactate threshold. Interval (I): hard 3–5 min reps at ~97–100% VO2 max. Repetition (R): short, fast repeats at 105–120% VO2 max for speed and economy.

Which race distance gives the most reliable VDOT?

A 10K or half-marathon run at full race effort tends to give the most reliable VDOT because these distances stress both the aerobic engine and race-specific pacing. A 5K result is reliable too. Marathon results can underestimate VDOT if fueling or pacing was poor.

Can I use a training run instead of a race?

You can enter any timed run, but VDOT is calibrated for maximum-effort race performances. A training run done at sub-maximal effort will underestimate your true VDOT and produce paces that are too conservative.

How often should I recalculate my VDOT?

Recalculate after each significant race or hard time trial — typically every 4–8 weeks during a training block. As your fitness improves, your VDOT rises and your training paces should be updated accordingly.

VO2 Max from Race Time Calculator

Enter any race finish time and distance to get your estimated VO2 max (VDOT) using the Jack Daniels formula.

Race Result

Race Distance

Finish Time

hrs

min

sec

Enter a race result on the left,
then click Calculate to see your VDOT and training paces.

Estimated VO2 Max (VDOT)

mL/kg/min

Training Paces (Jack Daniels)

Zone	per Mile	per km	% VO2 Max

Jack Daniels VDOT method — Daniels' Running Formula

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Summary

This calculator uses the Jack Daniels VDOT formula to estimate your aerobic capacity (VO2 max) from a race finish time. VDOT is a performance-based proxy that correlates closely with lab-measured VO2 max while being far more practical — just enter a recent race result. Once your VDOT is known, the tool derives personalized training paces for Easy, Marathon, Threshold (Tempo), Interval, and Repetition efforts, so you can train at exactly the right intensity for each workout.

How it works

Select your race distance — 1500 m, mile, 5K, 10K, half marathon, or marathon.
Enter your finish time in hours, minutes, and seconds.
Click Calculate to run the Jack Daniels VDOT formula.
Your estimated VO2 max (VDOT score) appears at the top of the results.
Five training paces — Easy, Marathon, Threshold, Interval, and Repetition — are displayed per mile and per kilometer.
Use the training paces directly to plan workouts within the Daniels running framework.

Use cases

Determine training paces after a recent 5K or 10K race.
Compare fitness progress by recalculating VDOT after each tune-up race.
Set realistic marathon and half-marathon goal paces from shorter race results.
Coaches can assign data-driven interval and tempo paces to athletes.
Validate whether your current easy-run pace falls in the correct aerobic zone.
Use VDOT trend over multiple races to track long-term fitness development.
Check if a goal race time is realistic before committing to a training cycle.
Cross-check treadmill or track workout paces against race-derived benchmarks.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu