VDOT calculator
Turn a race result into Jack Daniels’ VDOT fitness score, the five training paces it prescribes, and what you should be able to run at other distances.
Works for races from 1500 m and longer than 3½ minutes.
Your training paces
| Zone | Pace /km | What it’s for |
|---|---|---|
| E · Easy | 6:03 – 6:57 | Most of your weekly running, recovery and long runs. |
| M · Marathon | 5:38 | Goal marathon pace; long-run segments. |
| T · Threshold | 5:16 | Comfortably hard: tempo runs of 20 min or cruise intervals. |
| I · Interval | 4:51 | Hard 3–5 min repeats with equal jog recovery. |
| R · Repetition | 4:36 | Short fast 200–400 m reps for speed and economy. |
Equivalent race times
Why a 5K and a marathon give the same VDOT
The formula has two halves. First, the oxygen cost of your race pace. Second, the share of your VO2max you can sustain for that long: nearly all of it for a few minutes, much less for hours. Dividing one by the other gives the same fitness number whichever race you use. Drag the race duration.
Reference points:
Above 100% for very short efforts means some energy comes anaerobically. It’s why a marathon at 80% sits on the same fitness line as a 5K at around 95%.
Where VDOT comes from
Exercise physiologist Jack Daniels and mathematician Jimmy Gilbert fitted two equations to data from runners of all levels (Oxygen Power, 1979). One gives the oxygen cost of running at a given speed; the other gives the fraction of VO2max a runner can sustain for a given time. Your race is the one point where both are known, so it pins down your VDOT.
The training paces come straight from that number: Easy at about 62–74% of VDOT, Threshold at 88%, Interval at 97.5%, and Repetition slightly faster than interval pace. Marathon pace is simply your predicted marathon time spread evenly. Log races in your running log and it shows your best VDOT automatically; compare with the simpler Riegel race predictor.
Planning easy miles after dark? Night runners know the full Moon as a free headlamp; ahaboo shows why it only lights the trail for a few nights each month.
Questions runners ask
What is VDOT?
VDOT is Jack Daniels’ running-fitness score, from Daniels’ Running Formula. It is the VO2max value that would explain your race performance given typical running economy. Two runners with the same VDOT should race about the same times, whatever their lab VO2max.
Is VDOT the same as VO2max?
No. VO2max is measured in a lab. VDOT is derived from a race result, so it bundles in your running economy and race-day ability. It is often called an “effective” VO2max and is the more useful number for setting paces.
What is a good VDOT score?
A 25:00 5K is a VDOT of about 38; sub-20 minutes is about 50; elite men’s 5K runners sit above 80. Rather than comparing with others, use VDOT to track your own fitness and set training paces.
How often should I update my VDOT?
After each all-out race, or every 4–6 weeks from a time trial. Daniels suggests moving up by no more than one VDOT point at a time between races so training paces stay manageable.