VDOT Calculator (Jack Daniels)

VDOT — short for "V-dot-O2" — is Jack Daniels' proprietary running fitness score. Daniels designed it to produce a single number that predicts race times across any distance and dictates appropriate training paces. Once you have your VDOT, a lot of programming decisions become paint-by-numbers.

Why VDOT Is Useful

• One race result predicts performance across all distances
• Training paces scale automatically as you improve
• Combines aerobic capacity and running economy into one number
• Widely used by coaches and adopted by running communities worldwide

The Five Training Intensities

• Easy (E) — ~65-78% VDOT: The bulk of your mileage. Conversation pace. Builds aerobic base and aids recovery.
• Marathon (M) — ~80-85% VDOT: Used in marathon-specific training blocks.
• Threshold (T) — ~86-90% VDOT: Comfortably hard. Raises your lactate threshold.
• Interval (I) — ~95-100% VDOT: Hard. Develops VO2 max via 3-5 min intervals.
• Repetition (R) — ~105-120% VDOT: Fast, short bursts for speed and economy.

Getting the Best Result

Use a race where you gave full effort within the past 4-6 weeks, preferably in good conditions. Fueling, pacing mistakes, heat, and hills all depress your VDOT below your true fitness. If you race rarely, a hard 5K time trial works just as well.