VDOT calculator, training paces & quality workouts.
One number → race-time predictions across 11 distances, the five Daniels paces (E·M·T·I·R) at every track segment from 200 m to a mile, heat / altitude correction, HR-zone overlay and ready-to-run workout templates.
step 1
step 2
Use the Adjust tab to correct for heat or altitude. Your input persists between visits.
what's next
- → — E/M/T/I/R at every track segment
- → Equivalent race times — what you should run at 1500m through marathon
- → Adjust for race-day heat or altitude
- → Definitions — pace purpose, %HRmax, sample workouts
Frequently asked
What is VDOT?
VDOT is Jack Daniels' running performance metric — a single number that captures VO2max and running economy. From one race result we can derive your training paces and predicted times across distances.
How accurate is the VDOT calculator?
It uses the published Daniels-Gilbert formula and is the industry standard for race prediction and pace prescription. Most predictions are within 1-3% when fitness is current and the input race was honest.
Can I enter pace instead of time?
Yes — toggle to pace mode and enter min:sec per mile or km. We back-calculate the total time for the chosen distance.
Do temperature and altitude really matter?
Yes. Heat above 55°F costs ~0.5%/°F and altitude above 3000ft costs ~2%/1000ft. Toggle the environmental adjustments to apply them.
How often should I retest my VDOT?
Every 4-8 weeks during a structured block, or after any clean race result. As fitness improves, your VDOT should climb 1-3 points per training cycle.
VDOT is Jack Daniels' single-number proxy for running fitness — a way to express the VO2max you'd need to produce the race result you just ran, after correcting for how long you held it (because you can't hold 100% of VO2max for an hour). The Daniels–Gilbert equations behind this VDOT calculator are two curves: an oxygen-cost curve that converts running velocity into ml/kg/min, and a duration curve that says what fraction of VO2max you can sustain for a given race time.
VO₂ = −4.60 + 0.182258·v + 0.000104·v² // v in m/min %max = 0.8 + 0.1894393·e^(−0.012778·t) + 0.2989558·e^(−0.1932605·t) // t in min VDOT = VO₂ ÷ %max
Worked example. Run 5K in 20:00. Velocity is 5000 m ÷ 20 min = 250 m/min. Plug into the cost curve: VO₂ ≈ −4.60 + 45.56 + 6.50 ≈ 47.5 ml/kg/min. Plug 20 minutes into the duration curve: %max ≈ 0.93. So VDOT ≈ 47.5 ÷ 0.93 ≈ 51 — which lines up with a ~3:23 marathon equivalent and an Easy pace near 5:00/km.
From that one number you get every training pace this page shows: Easy (E) at 59–74% of VDOT, Marathon (M) at ~84%, Threshold (T) at ~88%, Interval (I) at ~98%, and Repetition (R) at >100% but over very short intervals. Heat above 60 °F and altitude above 3,000 ft both raise the cost of holding the same velocity, which is why the environmental toggle above slows the recommended paces.
Jack Daniels VDOT: The Complete Guide
What VDOT measures, how to calculate it, and how to translate it into easy, threshold, interval, and repetition paces.
Marathon Pace: Picking a Goal You Can Actually Run
Use VDOT + recent half marathon + weekly volume to lock in a realistic marathon goal pace.
Zone 2: Why Slow Training Builds Fast Athletes
Easy pace from your VDOT is the engine room of every PR — here's how to use it.
Ironman & 70.3 Time Predictor
How standalone race times translate to long-course finish splits.
Triathlon time predictor
Carry your VDOT pace into Sprint, Olympic, 70.3 and Ironman finish-time splits.
Heart rate zone calculator
5 HR zones from threshold or max HR — pair with VDOT paces for dual-metric runs.
Heat & humidity pace calculator
Adjust your VDOT goal pace for race-day temperature and humidity.
Marathon pace calculator
Goal-pace splits, halves and km/mile breakdowns — built off VDOT.
Want a plan built around your VDOT — not a generic template?
VDOT tells you what paces to run. A coach tells you when, in what order, and what to cut when life gets in the way. That's where 1:1 work pays for itself.
Boston-based · Trilingual EN/PT/ES · RRCA · USAT · TrainingPeaks L2 · 12× Boston qualifier