Jack Daniels VDOT Calculator — enter any race time and instantly get your VDOT score.
Race Distance
Race Time
Training paces explained
Easy pace: Should feel genuinely conversational — if you cannot complete a full sentence, you are running too hard. Run the bulk of your weekly mileage here to build aerobic base and support recovery between harder sessions.
Marathon Pace: You can speak in short phrases but not hold a full conversation. Use M-pace for long progression runs or medium-long mid-week efforts when preparing for 42 Km. Marathon pace long runs are typically 16–26 KM for experienced athletes.
Threshold pace: The T zone is the cornerstone of the Jack Daniels training system. Tempo runs raise your lactate clearance rate, directly increasing the speed you can sustain in races. A classic session is a 20-minute continuous effort or 3–4 × 8-minute intervals at T-pace with 1-minute recovery jogs. Threshold pace should feel "comfortably hard" — sustainable for roughly 60 minutes of race effort.
Interval Pace: I-pace develops VO2max directly. These are hard 3–5 minute efforts near your 3K–5K race paces, with equal recovery between reps. Limit I-pace work to roughly 8% of weekly mileage — the high physiological cost requires adequate recovery to be effective.
Repetition Pace: R-pace targets stride efficiency and raw speed. Short 200–400m efforts at fast race paces with full recovery improve neuromuscular efficiency, making your E-pace and T-pace feel more comfortable at equivalent effort. Stride gains compound over a full training cycle and directly improve running economy.