VDOT is a single fitness number from Jack Daniels' running formula. It is derived from a VO2max model: a faster race performance produces a higher VDOT, and equal VDOTs across distances represent equivalent fitness.

How is VDOT calculated here?

The tool uses the Daniels–Gilbert equations. It computes VO2 = -4.60 + 0.182258·v + 0.000104·v² (v = velocity in metres per minute), then divides by the fraction of VO2max sustainable for that race duration.

What distances can I score?

Anything from 1500 m, the mile, 3000 m, 5 km, 10 km and the half marathon up to the full marathon. Each is converted to its exact metre distance before the calculation.

Why does the same VDOT give different paces at different distances?

A runner can hold a higher fraction of VO2max for a 5 km than a marathon. The model accounts for this, so one VDOT maps to a faster pace over short distances and a slower pace over long ones.

Is VDOT the same as VO2max?

No. VO2max is a lab-measured oxygen-uptake value. VDOT is a "pseudo VO2max" inferred from race performance that bundles in running economy, so it is a practical proxy rather than a physiological measurement.

How do I use my VDOT score?

It sets equivalent race times and training paces (easy, marathon, threshold, interval, repetition). A higher VDOT after a few weeks of training is direct evidence your fitness has improved.

Is my race data uploaded?

No — the calculation runs entirely in your browser and nothing leaves your device.

VDOT Running Calculator

VDOT is Jack Daniels’ single-number running-fitness score, built on the Daniels–Gilbert VO2max model. Enter any race result from 1500 m to the marathon and the calculator returns the VDOT that performance represents. Because equal VDOTs across distances reflect equivalent fitness, coaches and self-coached runners use the number to set training paces and to compare, say, a 5 km against a half marathon.

How it works

The calculator converts your race into a velocity, models the oxygen cost of that velocity, then adjusts for how long you can sustain it.

Velocity: v = distance (m) / time (min) in metres per minute.
Oxygen cost: VO2 = -4.60 + 0.182258·v + 0.000104·v².
Sustainable fraction: %VO2max = 0.8 + 0.1894393·e^(-0.012778·t) + 0.2989558·e^(-0.1932605·t), where t is race time in minutes — shorter races allow a higher fraction.
VDOT = VO2 / %VO2max, rounded to one decimal place.

Example

A 5 km in 22:30 gives v = 5000 / 22.5 = 222.2 m/min. Then VO2 = -4.60 + 0.182258·222.2 + 0.000104·222.2² ≈ 41.0, and %VO2max ≈ 0.946, so VDOT ≈ 41.0 / 0.946 ≈ 43.4.

Race	Time	Approx. VDOT
5 km	25:00	~39
5 km	22:30	~43
5 km	20:00	~49
10 km	40:00	~50

The whole calculation happens locally in your browser — nothing is uploaded.