Built by Tommo, Verus founder — free to use, no account required.
VO2 Max Calculator
Your aerobic ceiling, estimated from a race rather than a lab.
VO2 Max Calculator
Estimate your running VO2 max from a race you have actually run — no lab, no treadmill test.
Your recent race
Estimated running VO2 max
40.0ml/kg/min
What that predicts at other distances
| 5K | 23:59 |
| 15K | 1:16:51 |
| 10 Mile | 1:22:48 |
| Half Marathon | 1:50:19 |
| Marathon | 3:50:01 |
The training paces it implies
| Easy (E) | 5:51–6:59 /km |
| Marathon (M) | 5:17–5:47 /km |
| Threshold (T) | 5:05–5:20 /km |
| Interval (I) | 4:36–4:47 /km |
| Repetition (R) | 3:58–4:25 /km |
This is a running-specific estimate derived from a race performance, not a laboratory measurement. A real VO2 max test measures oxygen consumption directly and will usually give a different number, because a race result also reflects running economy, pacing and how hard you were willing to go on the day. Use it to track your own change over time rather than to compare yourself with someone else's lab result.
Use It On A Real Race
About This Tool
VO2 max is the maximum rate at which your body can take in and use oxygen, and it is the single most quoted number in endurance sport. Measuring it properly needs a mask, a treadmill and a laboratory. Estimating it from a race result needs only a race result — and for a runner, the estimate is arguably the more useful number, because it already contains your running economy rather than treating it separately. This calculator uses the published Daniels-Gilbert oxygen-cost regression, the same model behind the training pace calculator on this site, so the VO2 max here and the paces there always agree.
How To Use It
- Pick the distance of a race you have genuinely run, and run hard.
- Enter the time. The more recent the result, the more it reflects your current fitness.
- Read the VO2 max estimate, then the equivalent times it predicts at every other distance.
- Use the training paces underneath it to set your actual week, rather than training off the number itself.
- Re-test every four to six weeks during a training block — a stale race result produces stale paces.
What VO2 max actually measures
VO2 max is the maximum rate at which your body can take in oxygen, transport it to working muscle and use it. It is expressed in millilitres of oxygen per kilogram of body mass per minute, which is why the units look the way they do, and it is one of the better single predictors of endurance performance ever found.
It is also, on its own, less useful than its reputation suggests. Two runners with identical VO2 max values can race very differently, because performance also depends on running economy — how much oxygen you actually burn at a given pace — and on the fraction of your maximum you can hold for the duration of the race. A high ceiling you cannot get near for an hour is not much use over a half marathon.
That is precisely why an estimate derived from a race result is arguably more useful to a runner than a laboratory number. A race already contains your economy and your sustainable fraction. It measures what you can do, not what you theoretically could.
How this calculator gets there
It works backwards from the pace you sustained. The Daniels-Gilbert model gives the oxygen cost of running at a particular velocity, and separately gives the percentage of VO2 max a person can sustain for a given duration — a percentage that falls the longer the effort lasts, which is why a marathon is not simply a long 5K.
Divide the oxygen cost of your race pace by the percentage you could have been holding for that long, and you have an estimate of the maximum. No mask, no treadmill, no laboratory.
One model, used consistently
This is the same regression that drives the training pace calculator on this site. That is deliberate: a VO2 max on one page and training paces on another that were computed from different models would quietly disagree, and runners would have no way of knowing which to trust.
What common race times produce
Computed with the same model the calculator above uses, so you can check any row of it yourself.
| 10K time | Estimated VO2 max | 5K time | Estimated VO2 max |
|---|---|---|---|
| 35:00 | 60.7 | 18:00 | 56.3 |
| 40:00 | 51.9 | 20:00 | 49.8 |
| 45:00 | 45.3 | 22:00 | 44.5 |
| 50:00 | 40.0 | 25:00 | 38.3 |
| 55:00 | 35.8 | 30:00 | 30.8 |
| 60:00 | 32.3 | 35:00 | 25.6 |
Notice that the 5K and 10K columns do not line up exactly — a 20:00 5K and a 40:00 10K are roughly equivalent performances but produce slightly different estimates. That is the model being honest rather than broken: the two efforts sit at different points on the duration curve, and small differences in your own endurance profile show up as a gap between them.
Which race to use
Something between 5K and half marathon, run as an actual race rather than a hard training run.
- A recent 10K is usually the best single input. It is long enough to be aerobically dominated and short enough not to be decided by fuelling.
- 5K works well and is easier to test regularly. parkrun makes it close to free, which is why so many people use it as their benchmark.
- Half marathon is good if you are well trained for the distance, and misleading if you are not.
- Marathon results tend to understate aerobic capacity, because the race is limited by fuelling, durability and pacing at least as much as by oxygen delivery.
- Anything shorter than 5K starts to be dominated by speed and anaerobic capacity, which this model is not trying to measure.
What the number cannot tell you
Three honest limits, because a calculator that presents an estimate as a measurement is doing its user a disservice.
First, it is not a laboratory VO2 max and will usually differ from one. A lab test isolates oxygen consumption under a controlled protocol; a race result bundles in economy, pacing judgement and how much you were willing to hurt on the day. Both are real numbers, but they are answering slightly different questions.
Second, it says nothing about why your number is what it is, and therefore nothing about what to do next. A runner whose VO2 max is high but whose marathon times disappoint has an endurance and fuelling problem, not an oxygen problem, and no amount of interval training will address it.
Third, comparison across people is close to meaningless without controlling for age, sex and training history. The percentile tables circulating online disagree with each other substantially, which is why this site does not publish one. What the number is genuinely good for is comparison with yourself, six weeks ago.
Improving it
VO2 max responds to training, and it responds fastest in the least-trained. The specific stimulus is work at around 95-100% of VO2 max — intervals of roughly three to five minutes, hard enough that you could race the effort for about ten to twelve minutes if you had to.
But the reason most runners improve is not the intervals. It is the volume of easy running underneath them, which builds the aerobic machinery that lets you do the hard sessions at all and recover from them. This is why every well-built training week puts the large majority of its mileage at genuinely easy pace, and why running easy days too hard is the most common way to stall.
Related Tools
Frequently Asked Questions
How do you calculate VO2 max from a running race?
By working backwards from the oxygen cost of the pace you sustained. The Daniels-Gilbert model calculates the oxygen cost of running at your race velocity, then divides it by the percentage of VO2 max a person can sustain for that duration — which falls the longer the race lasts. That gives a running-specific VO2 max without any laboratory equipment.
Is a calculated VO2 max accurate?
It is an accurate estimate of running performance and an approximate estimate of laboratory VO2 max. The two differ because a race result also reflects running economy, pacing and willingness to hurt, while a lab test isolates oxygen consumption. Use the number to track your own change over time rather than to compare against someone else's lab result.
What is a good VO2 max for a runner?
It depends entirely on age, sex and training history, and chasing a number in isolation is a poor use of attention. The more useful reading is direction: a VO2 max that is rising across a training block means the block is working. Verus deliberately does not publish population percentile tables here, because the ones circulating online disagree with each other substantially.
Which race distance gives the best VO2 max estimate?
Something between 5K and half marathon, run as a genuine race effort. Very short efforts are dominated by speed and anaerobic capacity, and the marathon is dominated by fuelling and durability — both pull the estimate away from aerobic capacity. A recent 10K is usually the best single input.
What is the difference between VO2 max and VDOT?
VDOT is a VO2 max estimate derived specifically from race performance, which is exactly what this calculator produces. The distinction people draw is that a lab VO2 max measures oxygen uptake alone, while VDOT bundles in running economy — so two runners with the same lab VO2 max can have different VDOTs, and the VDOT is the better predictor of how they will actually race.
How quickly can you improve VO2 max?
Meaningful change takes months rather than weeks, and the least-trained runners improve fastest. Interval work at around 95-100% of VO2 max is the most specific stimulus, but it only works on top of a large base of easy running — which is why the training paces this tool produces put the majority of your week at easy pace.