PACECALC · iOS App

VDOT calculator

The Daniels fitness score from any recent race. Once you have a VDOT, every other PaceCalc training tool inherits it.

Recent race distance
Finish time
::

Your VDOT
44.5
Daniels' fitness score — saved across all calculators

Equivalent race times

Same VDOT · different distance
DistanceTimemin/mi
1 Mile6:376:37
10K45:527:23
15K1:10:307:34
Half Marathon1:41:127:43
Marathon3:31:008:03

Training paces from your VDOT

Daniels · 5 zones
ZonePurposemin/mi
Easy / RecoveryComfortable conversational pace8:38 - 10:21
Marathon PaceGoal marathon race pace7:48 - 8:33
Threshold (Tempo)Comfortably hard, lactate threshold7:31 - 7:53
Interval (VO2max)Hard effort, 3-5 minute repeats6:47 - 7:04
RepetitionFast, short repeats for speed5:51 - 6:31

See Training Paces for the full reference card, or Intervals for track-workout splits.

METHODOLOGY

How this calculator works

  1. VDOT and equivalent training paces

    VDOT is a single number that summarizes your aerobic fitness from a recent race performance. Daniels' tables map VDOT to equivalent times at every standard distance and to recommended paces for easy, marathon, threshold, interval, and repetition work. PaceCalc estimates VDOT from your inputs, then surfaces those equivalent paces.

    Jack Daniels, Daniels' Running Formula, 3rd edition, Human Kinetics, 2013. Tables for VDOT and zone-based pacing.

  2. Riegel formula

    The Riegel formula projects a finish time at one distance (T₂) from a known time at another (T₁) using T₂ = T₁ × (D₂/D₁)^1.06. The 1.06 exponent captures the typical fatigue curve for trained runners. PaceCalc uses 1.06 as the default; you can adjust the exponent on the race-predictor page if you fade harder than average.

    R. H. Riegel, "Athletic Records and Human Endurance," American Scientist, vol. 69, no. 3, 1981, pp. 285–290.

NOTES
  • VDOT is most accurate when calculated from a recent (within 4–6 weeks), well-paced race at a distance you trained for. Predictions across very different distances (5K → marathon) carry more uncertainty than near-equivalent ones (10K ↔ half).
  • Two runners with the same VDOT can race the same time at any equivalent distance — but they may need very different training volumes and recoveries to express that fitness.