VDOT Calculator (Jack Daniels)

Compute your Jack Daniels VDOT score from a recent race time. VDOT is a single-number proxy for current running fitness.

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How to use this calculator

  • Enter a recent all-out race distance and time.
  • Use a hard race effort (5K, 10K) for the most accurate read; longer races bias VDOT downward.
  • Read the VDOT number; use it with Daniels' tables to set training paces.

About this calculator

VDOT, defined by Jack Daniels in "Daniels' Running Formula", is a single number that estimates a runner's current aerobic fitness. It is computed from a recent race performance using a velocity-to-VO₂ regression and an exponential model of the fraction of VO₂max sustained at race effort. The number maps to training-pace tables that prescribe easy, threshold, interval, and repetition paces.

Frequently asked

What does VDOT actually measure?+
It is an estimate of your VO₂max corrected for the fraction of VO₂max you can sustain at race effort. Two runners with the same VDOT should have similar performances at all distances under similar conditions.
Which race distance gives the most accurate VDOT?+
A recent 5K or 10K all-out effort. Marathons tend to under-estimate fitness because pacing, hydration, and durability matter more than raw aerobic capacity.
How often does VDOT change with training?+
In novice runners, VDOT can rise 1-2 points per month with consistent training. Elite runners change <0.5 points per year.
Is VDOT the same as VO₂max?+
They are closely related but not identical. VDOT is a derived "working" VO₂max — it accounts for the fact that nobody races at exactly 100% of VO₂max.
How do I use VDOT to pick training paces?+
Daniels' tables map each VDOT to specific paces for easy runs, marathon pace, threshold, interval (vVO₂max), and repetition workouts. Many running calculators (and the McMillan-pace-equivalents tool) reproduce these.

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