What is VDOT?
VDOT is a measure of running fitness developed by renowned coach and exercise physiologist Dr. Jack Daniels. It represents your current running ability as a single number derived from a recent race performance. While closely related to VO2max (the maximum volume of oxygen your body can use during exercise), VDOT also accounts for running economy — how efficiently you use oxygen at a given pace.
Two runners may have the same laboratory-measured VO2max but different VDOT scores because one runs more efficiently than the other. This makes VDOT a more practical and accurate predictor of race performance than VO2max alone.
How to Use This Calculator
Enter a recent race result — ideally from the past 4-6 weeks — and the calculator will determine your VDOT score. From that score, it provides two key outputs:
- Equivalent Race Times — predicted finish times for standard race distances (5K, 10K, Half Marathon, Marathon) at your current fitness level.
- Training Paces — the optimal paces for each type of training run, including easy runs, marathon-pace workouts, tempo (threshold) runs, intervals, and repetitions.
Understanding the Training Zones
Each training zone in the Daniels system targets a specific physiological adaptation:
- Easy (E) — builds aerobic base, promotes recovery, and develops injury resistance. Most of your weekly mileage should be at this pace.
- Marathon (M) — practises race-specific pacing and fuelling strategy for the marathon distance.
- Tempo / Threshold (T) — improves your lactate threshold, the pace you can sustain for roughly 60 minutes in a race. Typically run as 20-minute sustained efforts or cruise intervals.
- Interval (I) — develops VO2max through hard efforts of 3-5 minutes with equal recovery. The primary pace for boosting aerobic power.
- Repetition (R) — improves running economy and speed through short, fast efforts (200-400m) with full recovery between reps.
Tips for Accurate Results
- Use a race result from the last 4-6 weeks for the most accurate VDOT.
- Choose a race where you gave a genuine all-out effort on a fair course.
- If your 5K and marathon VDOT scores differ significantly, it may indicate a training imbalance — you can target the weaker area.
- Re-test every 4-6 weeks as your fitness changes to keep training paces current.