VDOT Calculator: Your Race Paces and Training Zones
Enter a recent race. Get your VDOT score, your equivalent race times at every common distance, and the exact paces you should be training at — easy, marathon, threshold, interval, and repetition. Built on Jack Daniels' Running Formula, free to use.
VDOT Calculator
Equivalent race times
| 1 mile | 5:51 |
| 5K | 20:00 |
| 10K | 41:28 |
| Half marathon | 1:31:50 |
| Marathon | 3:11:17 |
Training paces
Easy (E) Daily runs, long runs, recovery | 8:39 |
Marathon (M) Marathon race pace | 7:18 |
Threshold (T) Tempo runs, 20–60 min comfortably hard | 6:52 |
Interval (I) 3–5 min reps at VO₂max | 6:18 |
Repetition (R) Short fast reps, 30–90 sec | 5:57 |
What is VDOT?
VDOT is a single number that represents your current running fitness. It was developed by Jack Daniels, one of the most respected running coaches of the last 50 years, and is the foundation of his book Daniels' Running Formula.
Your VDOT is calculated from a recent race time. The formula accounts for two things at once:
- The oxygen cost of running at a given pace (faster paces require exponentially more oxygen per minute).
- The percentage of your maximum aerobic capacity you can sustain for that race duration (you can hold a higher percentage of your max for 5 minutes than for 2 hours).
The result is a number — typically between 30 and 85 for most runners — that translates directly into predicted race times at other distances and into precise training paces. A VDOT of 50 corresponds to roughly a 20:16 5K and a 3:14 marathon. A VDOT of 60 is a 17:03 5K and a 2:43 marathon.
How to use your VDOT for training
The real value of VDOT isn't the score itself — it's the training paces that fall out of it. Most runners guess their easy, tempo, and interval paces by feel. Feel lies. VDOT gives you a physiologically-grounded pace for each type of workout so that every run does what it's designed to do.
Easy pace (E)
The pace for 75–85% of your weekly mileage. You should be able to hold a conversation. This is where you build aerobic base, capillary density, and injury resilience. Most runners run their easy days too fast — the biggest single mistake in amateur training. See our guide on rest and recovery.
Marathon pace (M)
Your projected marathon race pace. Use this on marathon-pace long runs and marathon-specific workouts. Even if you aren't training for a marathon, M-pace segments are useful at the end of long runs to build durability.
Threshold pace (T)
"Comfortably hard" — the pace you could race for about an hour. This is lactate-threshold work and the most productive single workout in your training week. Use it for tempo runs, cruise intervals, and threshold repeats. If you want to learn more, start with our heart rate training guide.
Interval pace (I)
Roughly your 10–12 minute race pace. Used for 3–5 minute VO2max intervals with equal-time recovery. This develops your aerobic ceiling. Less is more — too much I-pace work burns runners out.
Repetition pace (R)
Short, fast repeats (30–90 seconds) with full recovery. The goal is neuromuscular improvement and running economy, not aerobic stress. Stop when form breaks down.
When to retest your VDOT
Every 4–8 weeks in a training block, or after any goal race. Your fitness is a moving target — using last season's paces means you're training too hard (if you've improved) or too easy (if you haven't). The calculator costs nothing to rerun, so check in often.
Limitations of VDOT
VDOT is an excellent tool but it isn't perfect:
- It rewards races, not lab tests. Your VDOT is only as good as the race you input. A race run in 90°F heat, on a hilly course, or with bad pacing will under-represent your fitness.
- Long predictions assume long-run fitness. Predicting a marathon from a 5K assumes you have the endurance base to support it. If your longest run is 10 miles, the marathon prediction will be too optimistic.
- It doesn't account for environment or terrain. Trail, heat, cold, altitude, and wind all affect actual race times. Use VDOT for flat-ground, good-weather predictions.
- It rounds individual variation. Running economy varies between runners with the same VO2max. Two runners with VDOT 50 may have slightly different ideal training paces based on biomechanics and fiber-type composition.
Frequently asked questions
Which race time should I use?
A recent 5K or 10K is best. Race durations of 15–50 minutes fit Daniels' formula most accurately. Avoid anything shorter than 3 minutes or longer than 4 hours.
Is VDOT the same as VO2max?
No. VO2max is a lab-measured value. VDOT is a pseudo-VO2 derived from race performance. It captures VO2max, running economy, and race-day execution together — which is usually more useful than the raw lab number.
Why is my predicted marathon slower than I expected?
Daniels' formula assumes you've built the endurance to race the distance. If you're a 5K specialist trying to predict a marathon, the number is honest — it's telling you that 5K speed alone doesn't translate. Build your long run and easy mileage for 12–16 weeks before expecting the prediction to hold.