VDOT is Jack Daniels' shorthand for an "effective VO2max" derived from race performance. Rather than measuring oxygen uptake in a lab, VDOT backs out the equivalent aerobic capacity from your finish time. It captures both your true VO2max and your running economy in one number, making it a practical training predictor.

How accurate is the VDOT estimate?

VDOT is accurate when the race was run at maximum sustainable effort on a flat course in good conditions. Hilly courses, heat, wind, or a poorly paced effort will shift the result. Use a goal race or a recent well-paced time trial for the best input data.

Why do different distances give different VDOTs?

Each race distance stresses different energy systems. A 1500m favors speed; a marathon favors fat oxidation and mental resilience. Most runners are relatively stronger at one distance. If your VDOTs from different races differ by more than 2–3 points, consider training the weak distance to become more balanced.

What is the Easy pace zone for?

Easy runs build aerobic base, promote recovery, and account for 70–80% of weekly mileage in most training plans. Running too fast here is the most common training mistake — it accumulates fatigue without additional aerobic benefit. The correct easy pace should feel genuinely comfortable: you can hold a full conversation.

How often should I update my VDOT?

Update it after every meaningful race or time trial — typically every 4–8 weeks of consistent training. A 1 VDOT point improvement is roughly equivalent to a 1–2% improvement in race performance, which represents solid fitness progress.

Running VO2max Daniels Calculator

Enter a race distance and finish time to estimate your VDOT (VO2max proxy) and get Jack Daniels training pace zones.

Race Input

Race Distance

Finish Time

hours

minutes

seconds

Pace Display

min/km min/mile

Estimated VDOT

—

effective VO2max (ml·kg⁻¹·min⁻¹)

Training Pace Zones

Pace per km

Zone	Purpose	Pace Range

Based on Jack Daniels' Running Formula (3rd ed.)

Enter a race time to see your VDOT and training paces

Summary

This calculator uses Jack Daniels' VDOT method to estimate your effective VO2max from any race finish time and translate it into five training pace zones. VDOT is the foundation of Daniels' Running Formula — it lets you set Easy, Marathon, Threshold, Interval, and Repetition paces that are matched to your current fitness rather than arbitrary rules of thumb. Enter a recent race time and get ready-to-use paces for every type of workout in your plan.

How it works

Select a standard race distance (1500m through marathon) or enter a custom distance.
Enter your finish time in hours, minutes, and seconds.
The calculator computes the velocity as a fraction of VO2max using Daniels' performance curve.
VDOT is derived by finding the VO2max value that fits your race performance.
Five training zones (Easy, Marathon, Threshold, Interval, Repetition) are scaled from your VDOT.
Each zone shows a per-mile and per-kilometer pace range.

Use cases

Set realistic training paces after a recent race.
Compare fitness across different race distances using a single VDOT number.
Determine the correct easy run pace to build aerobic base without overtraining.
Find threshold pace for tempo runs and cruise intervals.
Plan interval and repetition workouts at the right intensity.
Track fitness progress by comparing VDOT from races over time.
Coach runners by giving them science-backed target paces for each session type.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu