Is VDOT the same as VO2max?

No, despite the similar sound. VDOT also accounts for how economically you run. Two runners with identical VO2max can have clearly different VDOT values.

Which distance should I base it on?

Ideally something between 5 and 21 kilometres. Very short distances overestimate endurance, very long ones often underestimate it.

Do I need to use every training pace?

No. Most people get far with easy running plus one hard session a week. The other paces are there when you need them.

VDOT Calculator (Jack Daniels)

Enter race time → get VDOT and training paces

Race time

min

sec

Distance (km)

VDOT: 45.3

Training paces

Easy6:20 min/km – 5:18 min/km

Marathon (M)4:58 min/km

Threshold (T)4:42 min/km

Interval (I)4:13 min/km

Repetition (R)3:51 min/km

What VDOT is

VDOT is a measure of your current running form, developed by coach Jack Daniels. It comes from a race time and sums up how capable you are right now.

The practical use: from a single time — say your last 10K — the calculator derives how fast you should run in training. Easy, tempo, intervals: each gets a concrete number.

How it is calculated

VDOT = VO2 / %VO2max, following Jack Daniels. With v as speed in metres per minute: VO2 = −4.60 + 0.182258 × v + 0.000104 × v², and %VO2max = 0.8 + 0.1894393 × e^(−0.012778 × t) + 0.2989558 × e^(−0.1932605 × t), where t is the race time in minutes.

The second equation describes what share of their maximum a runner can hold for a given duration — short races sit closer to the maximum, so the share falls as time grows.

Example: 10 km in 45:00. v = 10000 / 45 = 222.2 m/min. VO2 = −4.60 + 40.50 + 5.14 = 41.0. %VO2max at 45 minutes = 0.907. VDOT = 41.0 / 0.907 = 45.3.

Training paces come from solving the equation backwards: easy runs at 59 to 74 % of VDOT, marathon pace at 80 %, threshold at 86 %, intervals at 98 %, repetitions at 110 %.

To calculate your VDOT, use a best time from an actual race — training times give a value that is too low.

How to work with it

Use a time from a real race or a serious time trial. A session where you held back produces paces that are too fast for training.

The value goes stale. After a few months of training a fresh test is worth it — otherwise you are training to yesterday's numbers.

Frequently asked questions

Is VDOT the same as VO2max?: No, despite the similar sound. VDOT also accounts for how economically you run. Two runners with identical VO2max can have clearly different VDOT values.
Which distance should I base it on?: Ideally something between 5 and 21 kilometres. Very short distances overestimate endurance, very long ones often underestimate it.
Do I need to use every training pace?: No. Most people get far with easy running plus one hard session a week. The other paces are there when you need them.