Your VDOT and training paces from one race.
Enter a recent race result and get your VDOT, estimated VO2max and five personalised training pace zones — Easy, Marathon, Threshold, Interval and Repetition — based on Jack Daniels' running formula.
Your race result
Your VDOT
Training pace zones
| Zone | Purpose | min/mile |
|---|---|---|
| E Easy / Recovery | Aerobic base, recovery | — |
| M Marathon | Race-pace stamina | — |
| T Threshold | Lactate clearance (tempo) | — |
| I Interval | VO2max stimulus | — |
| R Repetition | Speed & economy | — |
E range shown is the full easy band (slowest–fastest). T/I/R are target paces.
Predicted race times
| Distance | Predicted time |
|---|---|
| 1,500 m | — |
| Mile | — |
| 3,000 m | — |
| 5 K | — |
| 10 K | — |
| Half Marathon | — |
| Marathon | — |
How it's calculated
From race pace to training zones in three steps
VDOT is the oxygen consumption (VO2) that would theoretically produce your race performance, calculated using Jack Daniels and Jimmy Gilbert's 1979 formula. For example, a 25:30 5 K gives a VDOT of approximately 48, an estimated VO2max of 48 mL/kg/min, and an Easy pace range of around 9:45–10:30 min/mile (6:03–6:31 min/km). A 3:30 marathon yields VDOT ≈ 47.
Jack Daniels, Ph.D., derived the VDOT system from the relationship between running velocity and oxygen cost (VO2). Rather than measuring VO2max in a lab, the system back-calculates an "effective VO2max" from race performance — called VDOT — and uses it to prescribe five training zones that optimally stress different physiological systems.
%VO2max = 0.8 + 0.1894393·e−0.012778·t + 0.2989558·e−0.1932605·t
VDOT = VO2 / %VO2max
Where v is race velocity in m/min and t is race duration in minutes. The pace zones are then derived as fixed fractions of the VDOT value (i.e., fixed %VO2max targets), which translate back to running speeds via the inverse of the VO2–velocity relationship.
- 1Parse race time and convert to velocity (m/min)—
- 2Compute VO2 at race pace and %VO2max for that duration, then divide—
- 3Apply zone fractions to VDOT to get training velocities → paces—
Understand the terms
- VDOT
- Jack Daniels' practical fitness score derived from race performance. Numerically close to VO2max (mL/kg/min) but represents "effective" aerobic capacity — it encodes both fitness and running economy.
- VO2max
- Maximum oxygen uptake — the ceiling of the aerobic energy system, expressed in mL of O₂ per kg of body weight per minute. Higher values generally mean greater endurance potential.
- Threshold pace (T)
- The speed at which lactate production equals lactate clearance (lactate threshold). Sustainable for approximately 60 minutes for trained athletes. Training at T pace raises the threshold, making faster paces feel easier.
- Interval pace (I)
- Approximately 95–100% of VO2max effort. Used in repetitions of 3–5 min to maximise VO2max stimulus. Running faster than I pace offers diminishing returns.
- Repetition pace (R)
- Fast, short efforts (typically 200–400 m) run at mile race pace or faster, focusing on running economy and neuromuscular speed. Full recovery between reps.
- Easy pace (E)
- Conversational running at 59–74% of VO2max. Builds aerobic base, promotes recovery and supports mileage accumulation safely.
Frequently asked questions — VDOT
What is VDOT in running?
How do I calculate my VDOT?
What training paces does VDOT give me?
Which race distance gives the most accurate VDOT?
How often should I recalculate my VDOT?
📚 Learn more — official sources
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About the VDOT Calculator
The VDOT system was created by exercise physiologist and coach Jack Daniels, Ph.D., and published in Oxygen Power (1979, with Jimmy Gilbert). It remains one of the most widely used frameworks for prescribing running training paces. Unlike heart-rate zones, which require a separate lactate or VO2max test, VDOT is derived entirely from a race result that runners already have.
This calculator implements the Daniels–Gilbert equations numerically: it iterates over the full VDOT range to find the value whose associated race performance best matches your input. Training pace zones are then computed as the velocity at each zone's target %VO2max, converted to min/km and min/mile. Predicted race times are derived the same way — by finding the time at which each standard distance would yield your VDOT.