About the VDOT Running Calculator
This VDOT calculator turns a recent race result into the VDOT score from Jack Daniels’ running formula, then uses it to set your five training paces: easy, marathon, threshold, interval and repetition. Enter the distance and finish time of any race from 1500 m to the marathon and you get paces per kilometre or per mile, plus the race times your fitness predicts for other distances.
It is meant for runners following a Daniels-style plan, coaches setting workout paces for a group, and anyone who wants their training intensities tied to real performance rather than a guessed target time. Using a result from the last four to six weeks gives the most useful paces; recalculate after each race or time trial.
VDOT is a “pseudo VO2max”: it is the aerobic capacity that would explain your race time if you had average running economy. Two runners with the same lab VO2max can have different VDOTs, which is exactly why it works well for pacing. The race must be a genuine all-out effort on a flat course in good conditions; hills, heat or a jog-through will understate your fitness.
With the default inputs, the vdot is 38.3. Change any value above to recalculate instantly.
How to use the vdot running calculator
- 1Pick the distance of a recent all-out race or time trial.
- 2Enter your finish time in hours, minutes and seconds.
- 3Choose whether you want paces per kilometre or per mile.
- 4Read your VDOT and use the five paces to set easy runs, tempo runs, intervals and reps.
- 5Recalculate after each new race so your paces keep up with your fitness.
Formula and method
The calculator uses the two equations Jack Daniels and Jimmy Gilbert published in Oxygen Power (1979). The first gives the oxygen cost of running at race velocity v (metres per minute); the second gives the fraction of VO2max a runner can sustain for a race lasting t minutes. Dividing cost by the sustainable fraction gives VDOT, the effective VO2max your race implies.
Training paces come from inverting the oxygen-cost equation: easy pace is the speed whose oxygen cost is 62–70% of VDOT, threshold 88% and interval 97.5%. Marathon and repetition paces are the predicted race paces for the marathon and the mile, found by solving the VDOT equation for time. Results agree with the published Daniels tables to within a few seconds per kilometre.
- v
- Race velocity in metres per minute (distance ÷ time)
- t
- Race duration in minutes
- VO₂
- Oxygen cost of running at velocity v (ml/kg/min)
- %max
- Fraction of VO2max sustainable for t minutes
Worked examples
25:00 5K
A 25-minute 5K is 200 m per minute. Its oxygen cost is 36.0 ml/kg/min and a 25-minute effort can be held at about 94% of VO2max, so VDOT is about 38.3. That gives easy runs at 6:19–6:57 per km, threshold runs at 5:16 per km and intervals at 4:51 per km.
1:45:00 half marathon, paces in miles
A 1:45 half marathon averages 8:01 per mile and works out to a VDOT of about 42.6, because a 105-minute effort can be held at roughly 85% of VO2max. Threshold pace is 7:47 per mile — about 14 seconds faster than half-marathon race pace.
3:30:00 marathon
A 3:30 marathon is 4:59 per kilometre and implies a VDOT of about 44.6. Because the marathon itself is the reference race, the predicted marathon pace equals the actual one, and interval pace comes out at 4:18 per km.
Frequently asked questions
What is a good VDOT score?+
Recreational runners typically fall between 30 and 45, a 20-minute 5K runner is around 50, sub-3-hour marathoners are in the mid-50s, and elite distance runners reach 75–85. VDOT measures race fitness, so it rises as you get faster at any distance.
Is VDOT the same as VO2max?+
No. VDOT is a performance-based estimate that assumes average running economy. A runner with excellent economy will have a VDOT higher than their lab-measured VO2max, and an inefficient runner a lower one — which is why VDOT is better for setting paces.
Which race should I use?+
Use a recent all-out effort on a flat course, ideally 5K to half-marathon distance. Very short races overstate endurance and marathons are sensitive to fuelling and heat, so a 10K or half often gives the most balanced paces.
How often should I update my VDOT?+
Daniels suggests raising VDOT only after a new race result or after 4–6 weeks of consistent training at your current paces, and by no more than one point at a time. Do not raise it just because workouts feel easy for a single week.
Why is easy pace a range?+
Easy running covers roughly 59–74% of VO2max in Daniels’ system; this calculator shows the central 62–70% band, and any pace in it builds aerobic fitness. Run toward the slow end on recovery days and in heat, and toward the faster end on good days and long runs.