VDOT is Jack Daniels' practical running fitness score derived from race performance. It correlates closely with VO2max and provides a basis for calculating all your training paces — easy, marathon, threshold, interval, and repetition. Enter your recent race result to get your VDOT and personalized training paces.
Enter Your Race Result
How to Use the Running VO2max from Race Time Calculator
This VDOT calculator implements Jack Daniels' Running Formula to derive your fitness score and training paces from a recent race result. Enter a race you ran at true maximal effort for the most accurate estimate.
The Five Training Zones
Easy (E): Used for warm-ups, cool-downs, and recovery runs. Very conversational. Marathon (M): Goal marathon race pace. Threshold (T): Comfortably hard — approximately 1-hour race pace. Used for tempo runs and cruise intervals. Interval (I): Near VO2max pace for 3-5 minute repeats. Repetition (R): Faster than race pace for short 200-400m speed work.
Applying VDOT to Your Training
Most training (80%) should be at Easy pace. Threshold work (tempo runs) are the cornerstone of race fitness improvement. Interval and Rep work add speed and economy but should not exceed 15% of total weekly volume. Following this distribution closely mirrors the training of elite runners worldwide.
FAQ
Is this VDOT calculator free?
Yes, completely free with no signup.
What is VDOT?
VDOT is a practical running fitness value developed by Jack Daniels, PhD. It is calculated from race performances and correlates closely with VO2max but is slightly adjusted for running economy differences between athletes. Two runners with the same VO2max but different running efficiency can have different VDOTs.
How accurate is VO2max from race time?
Race-derived VO2max estimates using Daniels' formula are highly correlated with laboratory measurements (r > 0.95 in research). The main source of error is whether the race was run at maximal effort and in good conditions. Shorter races (5K, 10K) tend to give slightly inflated estimates due to significant anaerobic contribution.
What are the Daniels training pace zones?
Jack Daniels defines five training paces based on VDOT: Easy (E) — for recovery and aerobic base, Marathon (M), Threshold (T) — approximately 1-hour race pace for most runners, Interval (I) — near VO2max pace, and Repetition (R) — faster than race pace for speed. Each zone targets a specific physiological adaptation.
Which race distance gives the most accurate VO2max estimate?
The 10K gives the most reliable VO2max estimate because it is long enough to minimize anaerobic contribution but short enough to be run near maximal aerobic effort throughout. 5K results slightly overestimate VO2max. Half and full marathon results are reliable if fully raced at maximum sustainable effort.