VDOT is the closest thing distance running has to a single fitness number. Coined by exercise physiologist Jack Daniels in Daniels’ Running Formula, it represents your running-specific aerobic capacity — VO2max adjusted for running economy. A higher VDOT means you can produce more sustained running speed at the same level of physiological strain (Daniels, 2014).

What makes VDOT useful is that it works across distances. A single recent race result gives you a VDOT, and that VDOT predicts your equivalent times at every other standard distance. It also defines your training paces — easy, marathon, threshold, interval, and repetition — without you having to guess.

Definitions

VO2max: the maximum volume of oxygen your body can use per minute, normalized to body weight (ml/kg/min). Limited largely by genetics and trainable by 10-20% in most adults.
Running economy: the oxygen cost of running at a given pace. Two runners with the same VO2max can have meaningfully different paces at the same effort because of economy.
VDOT: a composite of VO2max and running economy, expressed as a single number. Coined by Daniels (2014).
Riegel formula: T2 = T1 × (D2/D1)^1.06, used to predict race times across distances (Riegel, 1981).

What VDOT numbers mean

VDOT is a continuous scale typically running from about 30 to 85 for human runners. Reference points:

VDOT 30: beginner runner. Roughly a 30:40 5K, 1:13 10K, 5:35 marathon.
VDOT 40: committed recreational runner. Roughly a 23:30 5K, 4:00 marathon (sub-4 sits at VDOT 41-42).
VDOT 50: strong amateur. Roughly a 19:50 5K, 3:14 marathon.
VDOT 60: sub-elite/competitive. Roughly a 17:00 5K, 2:45 marathon.
VDOT 70+: elite. Roughly a 14:00 5K, 2:21 marathon.

The scale is non-linear: gaining 5 VDOT points from 35 to 40 is dramatically easier than from 55 to 60.

How VDOT relates to VO2max

VO2max is a laboratory measurement (treadmill plus metabolic cart), and it correlates with running performance — but imperfectly. A runner with a 60 ml/kg/min VO2max and excellent running economy can outrun another runner with 65 ml/kg/min and average economy. VDOT collapses both factors into the single number that actually predicts race performance, which is why it’s the more practical metric for runners.

How to find your VDOT

Race something maximally, then plug the result into our race predictor. The tool computes your VDOT from the Daniels tables and projects your times at all common distances.

Best test events, in order of accuracy:

5K race (parkrun, local 5K). Long enough to be aerobic, short enough to be all-out. Best single test.
10K race. Slightly more aerobic; less subject to a bad day.
Half marathon. Good if you’ve raced one in the past 6-8 weeks.
3K time trial on a track. Great if you don’t have a recent race.

Avoid using a marathon time as your primary VDOT input unless you’re highly trained. Marathons tend to under-represent fitness for most recreational runners because of pacing errors and fueling issues; the predicted-from-5K marathon time is usually more accurate than the actual marathon time.

Predicting race times: the Riegel formula

The Riegel formula (Riegel, 1981) projects time across distances using the equation T2 = T1 × (D2/D1)^1.06. The 1.06 exponent reflects fatigue: doubling the distance doesn’t double the time, it slightly more than doubles it.

Worked example: a 20:00 5K runner. Riegel-predicted 10K = 20:00 × 2^1.06 = 41:38 (not 40:00). Riegel-predicted half marathon = 20:00 × (21.097/5)^1.06 = 1:32:30. Riegel-predicted marathon = 20:00 × (42.195/5)^1.06 = 3:13.

The accuracy degrades for the marathon because the formula assumes equally-trained endurance for all distances, which most 5K specialists don’t have. For most runners, Riegel predicts a marathon roughly 5-10% faster than they’re truly capable of without specific marathon training. Treat the marathon prediction as a fitness-based ceiling, not a target.

Training paces from VDOT

Daniels’ great practical contribution is converting VDOT into training pace ranges. Each VDOT defines paces for the five training intensities:

Easy (E): conversational, used for warm-ups, cool-downs, and recovery runs. Typically 60-90 sec/km slower than threshold.
Marathon (M): sustained marathon-effort pace.
Threshold (T): “comfortably hard,” around 1-hour race pace. Drives lactate threshold improvement.
Interval (I): 3-5 minute intervals at roughly current 3K-5K pace. Drives VO2max.
Repetition (R): 30-90 second efforts at roughly mile pace or faster. Drives running economy and neuromuscular speed.

Get your personal pace ranges with the training paces calculator.

How VDOT changes over time

For most recreational runners, VDOT improves 2-4 points over a 16-20 week training cycle. Beginners can see 5-8 point gains in their first year. Plateaus are common above VDOT 50; from there, additional gains require either substantially more volume, more years of consistency, or both.

The biggest drivers of VDOT improvement, in order:

Consistent weekly volume — months of unbroken training.
One threshold session per week — drives lactate threshold up the VDOT curve.
One VO2 session per week — raises the ceiling.
Sleep and nutrition.
Strength work. Improves running economy, especially for runners over 40.

Common VDOT mistakes

Re-testing too often. Day-to-day fitness fluctuates. Treat VDOT as a 4-6 week running average, not a daily readout.
Using a workout pace as a VDOT proxy. Workouts aren’t races. The 5K time you ran last week solo on a hilly route isn’t a VDOT input.
Trusting the marathon prediction without marathon-specific training. The Riegel/VDOT marathon estimate is a fitness ceiling, not a goal.
Comparing VDOTs across genders without context. The scale itself is unisex, but population distributions differ; “VDOT 50” is a different competitive level for men vs women in age-graded terms.
Targeting VDOT instead of training. VDOT is a measurement, not a workout. The way to improve it is to follow the plan, not to chase the number.

What this means for your training

Use VDOT for two things: (1) plan-fit decisions — am I aiming at the right race goal? — and (2) pace prescription — how fast should this workout actually be? Both are quietly transformative. Most runners overestimate or underestimate their fitness by a meaningful amount, and most run their workouts at the wrong intensity. VDOT fixes both.

Get your number from the race predictor. Pull your training paces from the training paces calculator. Browse VDOT-prescribed sessions in our banger workouts library.

FAQ

What’s a good VDOT? “Good” depends on context. VDOT 40 is solid recreational fitness. 50 is competitive amateur. 60 is sub-elite. 70+ is elite. The most useful comparison is to your past self, not to a benchmark.

Can I improve my VDOT in a month? Maybe by 1 point if you’ve been training poorly and clean up your distribution (more easy, more threshold). Meaningful gains over 2-3 points typically require 12+ weeks.

Why does my marathon VDOT come out lower than my 5K VDOT? Either you under-performed your marathon (pacing, fueling, weather), or your endurance lags your speed. The first is a one-day issue; the second is an indication that more long-run and threshold volume would help.

Is VDOT the same as VO2max? No. VDOT is a composite of VO2max and running economy. Two runners with identical VO2max in a lab can have different VDOTs because of economy differences.

How accurate is VDOT for the marathon? VDOT predicts marathon time accurately for runners who train specifically for the marathon (long runs to 32+ km, marathon-pace tempos, proper fueling). For 5K specialists who haven’t done marathon-specific work, the prediction is optimistic by 5-10%.

Does VDOT account for hills, heat, or altitude? No. VDOT assumes ideal conditions. Use our heat and altitude calculator for environmental adjustments, and grade-adjusted pace tools for hilly courses.

VDOT in practice: a worked example

Imagine a runner who ran 22:30 for 5K six weeks ago. Plugging that into the race predictor:

VDOT: 45.
Predicted 10K: 46:42.
Predicted half marathon: 1:43:31.
Predicted marathon: 3:35:20.

From those, the training paces calculator generates targets like:

Easy: 5:35-6:10/km.
Marathon pace: roughly 5:05/km.
Threshold: roughly 4:42/km, used in 20-30 minute tempo runs or 4 × 8 minute interval-tempos.
Interval (VO2): roughly 4:20/km, used in 1000 m repeats with 2:00 jog recovery.
Repetition: roughly 4:00/km, used in 200-400 m repeats with full recovery.

The runner now has a precise framework: the workouts have specific paces, the goal race has a specific time prediction, and any new race result is a new VDOT input that updates everything downstream. That’s the practical magic of the system — it converts one number into an entire training plan.

VDOT vs other prediction systems

Several alternatives exist. The most common:

Riegel formula alone (Riegel, 1981): simpler than VDOT and roughly equivalent for the 5K-half range. Less precise for the marathon. Doesn’t generate training paces.
Cameron formula: a marathon-tuned variant of Riegel that’s slightly more conservative for the marathon. Still doesn’t generate training paces.
Critical speed / power models: used by some advanced platforms. Different math, similar predictive accuracy for most distances.

For most runners, VDOT remains the most useful single number because it bundles prediction and prescription. You don’t have to pick a formula every time you ask a question.

What this means for your race calendar

Use VDOT to set ambitious-but-realistic goals across a season. Race a 5K in March, get your VDOT, build through summer, race a 10K in September, and target a goal half marathon or marathon in November or December. Each race result updates your VDOT, which updates your training paces, which updates the next race goal. The system keeps you honest about both progress and stagnation; if your VDOT hasn’t moved in six months despite consistent training, that’s signal that something in the plan needs to change — usually more easy volume, or more (and harder) threshold work.

How to Use VDOT to Predict Your Race Times.