Is VDOT Jack Daniels' formula?
Yes. VDOT comes from Jack Daniels, the running coach and exercise physiologist, and his colleague Jimmy Gilbert. They published the equations in their 1979 book Oxygen Power, and Daniels made VDOT famous in Daniels' Running Formula. The name is short for "V-dot-O2max," the symbol for VO2max.
Your VDOT isn't a lab VO2max test. It's a fitness score worked out from a real race. Two runners with the same VDOT should race about the same at every distance, which is why it's so useful for setting paces.
This calculator uses the published Daniels–Gilbert equations. Run Your Race isn't affiliated with Jack Daniels or the official VDOT O2 app. Paces may differ by a second or two from the tables in his book.
How the calculator works
- Your race speed → oxygen cost. The first equation estimates how much oxygen it takes to run your race pace.
- Your race time → % of max. The second equation estimates what share of your max you can hold for that long. You can hold close to 100% for a mile, and much less for a marathon.
- VDOT = oxygen cost ÷ % of max. Then the calculator works backwards from your VDOT to find the time at every other distance, and the speed for each training pace.
What each training pace is for
- Easy (E): most of your miles, including long runs. Conversational, about RPE 2–3 out of 10. If you're not sure, go slower.
- Marathon (M): your goal marathon pace, based on your current fitness.
- Threshold (T): "comfortably hard." Tempo runs and cruise intervals, about the pace you could race for an hour.
- Interval (I): hard repeats of about 3–5 minutes, with recovery jogs about as long.
- Repetition (R): short, fast repeats of 200–400 m, with full recovery, to work on speed and form.
Getting the best number
- Use a recent, all-out race, ideally from the last 6 weeks.
- A flat course in good weather. Hills, heat and altitude make your VDOT look lower than it is.
- A 5K, 10K or half marathon works best. Recalculate after each race as you get fitter.
- Training for your first marathon or ultra? Lean on your easy pace. That's where most of your training happens.
Fueling for a long race? Use my carb loading calculator, and read my 12 running tips I wish I knew when I started.
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Apply for coachingCommon questions
Who invented VDOT?
Jack Daniels and Jimmy Gilbert. They published the equations in their 1979 book Oxygen Power, and Daniels made VDOT famous in Daniels' Running Formula.
What does VDOT stand for?
It's short for "V-dot-O2max," the V with a dot over it used for VO2max. Daniels' VDOT isn't a lab test, though. It's a fitness score worked out from your race performance.
How accurate is a VDOT race prediction?
It's accurate when you've trained for the distance. A 5K predicts a 10K well, but it usually predicts a faster marathon than a newer runner can run unless they've done the long runs and mileage.
Which race should I enter into the running pace calculator?
A recent, all-out race on a flat course, ideally from the last 6 weeks. A 5K, 10K or half marathon works best.