Calculator
Estimate your VO2 max (maximal oxygen uptake: the most oxygen your body can use in all-out exercise) from a 12-minute run, the Cooper test, or from a fast 1-mile walk, your resting and maximum heart rates, or a 1.5-mile run. Each test names its formula and the people it was built on, and your result is compared with lab tests of US adults of your age and sex. It's an estimate: for one person any of these can be 5 to 10 points out, and an all-out run isn't for everyone, so read the short box above the inputs before you test.
Choose a test: the 12-minute run (the default), the 1-mile walk, the resting heart rate method or the 1.5-mile run. Read the "Before an all-out test" box, then enter your sex, age and the test's numbers, and tick a box if you take a medicine that slows your heart or you're pregnant.
42mL/kg/min
About 12.1 METs. In studies this was close on average in some groups, but up to about 8 too high or 20 too low for individual athletes.
Formula: (metres - 504.9) ÷ 44.73. Built in 115 men in the US Air Force (Cooper 1968).
Compared with US adults of your age and sex who had lab treadmill tests (FRIEND, 2015), your estimate is between the 50th and 75th percentile: above average. Norwegian volunteers your age averaged 47.2.
Higher fitness is strongly linked with a longer life, though no trial has shown that raising it causes that. VO2 max: what's good and how to raise it
VO2 max is per kilo, so the number rises if your weight falls even when your heart and lungs haven't changed. Training is what raises fitness. If thoughts about weight are affecting how you eat or exercise, see a GP or call Beat on 0808 801 0677.
A lab measures VO2 max with a mask that analyses your breath during an all-out treadmill or bike test. Field tests estimate it: the 12-minute and 1.5-mile runs track lab results best, but for one person an estimate is often 5 to 10 mL/kg/min (millilitres of oxygen per kilogram of body weight per minute) out, and sometimes 15 to 20.
Run as far as you can in 12 minutes: VO2 max = (metres - 504.9) ÷ 44.73. It came from 115 men in the US Air Force, and in 73 college athletes it read 6 low on average.
Built in 343 adults aged 30 to 69, it uses your walking time, your heart rate at the finish, your age, sex and weight. It read high in college students and a little low in older adults.
15.3 × maximum heart rate ÷ resting heart rate came from 46 well-trained men. In 66 men playing recreational football, it was up to about 15 out either way.
Your result is compared with 7,783 US lab tests from the FRIEND registry. Fitter people live longer on average, but no trial has shown that raising your VO2 max causes that.
The PAR-Q+ (Physical Activity Readiness Questionnaire for Everyone) asks people over 45 who aren't used to vigorous or maximal exercise to consult a qualified exercise professional first. The walk test is the gentler choice.
VO2 max is given in mL/kg/min. The calculator also shows METs (metabolic equivalents): 1 MET is 3.5 mL/kg/min, so METs = VO2 max ÷ 3.5. VO2 max is shown as a whole number and METs to one decimal place, because every method can be several points out (our choice).
Run as far as you can in 12 minutes, ideally on a 400 m track, and enter the distance in metres, km or miles. VO2 max = (distance in metres - 504.9) ÷ 44.73. Another study prints the same line as 22.351 × distance in km - 11.288, and the two agree to within 0.02 (our arithmetic).
Kenneth Cooper built the test in 1968 with 115 US Air Force officers and airmen, all men, whose 12-minute distance correlated 0.897 with a treadmill test. Only the paper's summary was available to us, so the equation comes from the later studies that reprint it.
Walk 1 mile (1,609 m: four laps of a 400 m track plus 9 m) as fast as you can, and note your time and your heart rate as you finish. VO2 max = 132.853 - 0.0769 × weight in pounds - 0.3877 × age + 6.315 × sex (1 for men, 0 for women) - 3.2649 × time in minutes - 0.1565 × heart rate at the finish. The calculator converts kg or stones and pounds to pounds, and minutes and seconds to decimal minutes, so 15:30 is 15.5.
Kline and colleagues built it in 1987 in 343 healthy adults aged 30 to 69, 165 men and 178 women, who walked a mile "as fast as possible" with their heart rate recorded. Use a chest strap or a wrist sensor: in a review, wrist sensors read within about half a beat of a chest strap or an electrocardiogram (ECG) when walking and running. Counting your pulse after you stop reads low, because your heart slows quickly, and a low reading pushes the estimate up (our reading).
VO2 max = 15.3 × maximum heart rate ÷ resting heart rate. Uth and colleagues found the factor of 15.3 in 10 well-trained men and tested it on 36 more, aged 21 to 51; with a measured maximum, the estimate's standard error was 2.7 mL/kg/min, and with an age-based maximum it was 4.7.
Take your resting heart rate the British Heart Foundation's way: sit or lie down for five minutes, with no caffeine or smoking beforehand, then count your pulse for 30 seconds and double it. Enter a measured maximum if you have one, or leave it blank and the calculator uses 208 - 0.7 × age, the estimate our heart rate zone calculator uses; the maximum has to be more than 40 beats above your resting rate.
Run 1.5 miles (2,414 m) as fast as you can and enter your time. VO2 max = 3.5 + 483 ÷ time in minutes. Two studies print it as the American College of Sports Medicine's (ACSM's) equation, and it's ACSM's running equation, VO2 = 0.2 × speed + 3.5 (speed in metres a minute, on the flat), applied to your average speed: 0.2 × 2,414 ÷ time is 482.8 ÷ time (our arithmetic).
We found no study that built or tested this formula on its own. The authors of the FRIEND norms note that ACSM's equations were validated only for steady exercise below maximum and "are known to overpredict" oxygen use at higher levels of exercise, so the result is labelled as one that may read high.
Each estimate is rounded to a whole number and placed against the FRIEND 2015 table, as the calculator shows it.
The Cooper equation is printed in metre, km and mile forms that agree to within 0.02 (our arithmetic). For the walk, Kline's summary names the heart rate over the last quarter-mile and a later study the heart rate after the walk, while another prints "resting pulse"; the calculator uses your heart rate at the finish, as the test was built.
Across 123 studies, the 1.5-mile run (18 studies, 873 people) and the 12-minute run (26 studies, 1,204 people) tracked measured VO2 max best of the walk and run tests, with pooled correlations of 0.79 and 0.78, and sex, age and fitness didn't change that. The authors stress that a field test's score is an estimate, "not a direct measure".
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In 73 college team-sport athletes it read 6.0 low on average, and for individuals it could be up to 7.9 too high or 19.8 too low. In 58 sedentary students it read 3.0 high against a bike test, in 22 young men who exercised regularly it was close on average (60.6 against 60.1), and in 21 young adults it read low at lower fitness and high at higher fitness.
Where it was built, in adults aged 30 to 69, the version in litres a minute correlated 0.93 with measured VO2 max, with a standard error of 0.325 litres a minute, and the version per kilogram was described as similarly accurate. In college students it "overpredicted VO2max by 16-18% in the males and by 22-23% in the females"; it was close in 24 Air Force men, missed the fittest and least fit Royal Navy personnel by 2 to 18%, and read about 2 low in adults averaging 68.
In the well-trained men it was built on, the standard error was 2.7 mL/kg/min with a measured maximum and 4.7 with an age-based one, and the authors said other groups would need testing. In 66 men playing recreational football, it read 1.9 high on average, and for individuals it could be up to 12.3 too low or 16.1 too high.
It's printed as ACSM's equation and matches ACSM's running equation at your average speed (our arithmetic), but we found no study that built it from measured VO2 max or tested it. The 1.5-mile run itself tracks VO2 max well, and ACSM's equations can read high at hard efforts.
Across 199 cohort studies, people with high fitness had about half the risk of death of those with low fitness, and each 1 MET higher went with an 11 to 17% lower risk. In 122,007 people having treadmill tests, the least fit had about 5 times the risk of the fittest, and the American Heart Association calls fitness a potentially stronger predictor of death than smoking, high blood pressure, high cholesterol or type 2 diabetes. The one long trial of exercise training, in 1,567 people aged 70 to 77, found no significant effect on deaths, with a trend favouring intervals.
Across 14 studies, watches that use your runs or walks were right on average but could be about 10 mL/kg/min out either way for one person, and those using resting data read about 2 high. The Apple Watch read about 6 low in two studies, and a Garmin Forerunner 245 about 4 to 5 low, and 6.3 low in highly trained athletes.
Heart problems during exercise are rare, but the risk is highest "when an adult who is usually inactive engages in vigorous-intensity activity". ACSM's screening rests on how active you are now, symptoms or known heart, metabolic or kidney disease, and how hard you plan to go. The PAR-Q+ and the UK's National Health Service (NHS) give the questions to ask yourself first.
It needs only a distance, and with the 1.5-mile run it tracks measured VO2 max best of the field tests. It's an all-out effort, so check the box above the inputs first.
It's a fast walk rather than an all-out run, and was built in men and women aged 30 to 69. You need your heart rate as you finish, from a chest strap or a watch. It read 16 to 23% high in college students.
It needs no exercise test, but it's most accurate with a measured maximum, from a maximal exercise test or the highest chest-strap reading from an all-out race or interval session. It doesn't work if a medicine slows your heart.
Use it if your club, service or school tests over 1.5 miles. Its formula hasn't been tested on its own and may read high.
Race-based scores such as Daniels' VDOT blend VO2 max with running economy, and VDOT read lower than lab VO2 max in a small study. Our running pace calculator predicts race times instead.
Estimates from a questionnaire alone exist: Jackson's 1990 model from 2,009 adults and Nes's 2011 model from 4,260 Norwegians had standard errors of about 5 to 6 mL/kg/min where they were built. But we couldn't check their activity scales against the original papers, and in a US cohort with a measured average of 34.9, the Nes model averaged 40.9 (in the 676 of 987 adults it could be worked out for), so we've left them out for now.
Running 1.5 miles in 12:00 gives 43.75 by the 1.5-mile formula, while covering the same 2,414 m in a Cooper test's 12 minutes gives 42.7. Each formula was built differently, which is why the calculator names the one it used.
US lab values in mL/kg/min from FRIEND 2015. The calculator places your estimate in a band between two percentiles for your age and sex.
The FRIEND registry (Fitness Registry and the Importance of Exercise National Database) gathered 7,783 maximal treadmill tests with breath analysis from 8 US laboratories in 2014 and 2015, in adults aged 20 to 79 without known heart disease. The calculator shows your band for your age and sex, for example "between the 50th and 75th percentile: above average", and uses the 5th and 95th percentiles too. Above the middle (the 50th percentile) is above average, and the top quarter (above the 75th) is high (our reading, as in our VO2 max guide). Outside 20 to 79 there are no FRIEND values, so there's no band.
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The 10th, 25th, 50th, 75th and 90th percentiles:
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The 10th, 25th, 50th, 75th and 90th percentiles:
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A 2022 update of the registry, with 22,379 tests, put treadmill values 1.5 to 4.6 mL/kg/min lower than these. Norwegian volunteers in the HUNT study scored higher, perhaps partly because healthier people volunteered, as its authors note; the calculator shows their average for your age and sex alongside your band. Their averages, men and women:
Fitness is strongly linked with a longer life: each 1 MET (3.5 mL/kg/min) higher went with an 11 to 17% lower risk of death across 199 cohort studies, and the least fit had about 5 times the risk of the fittest in 122,007 people having treadmill tests. These are observational links, and the one long trial of exercise training found no significant effect on deaths, with a trend favouring intervals. An estimate isn't a diagnosis; our VO2 max guide covers what's good for your age and how to raise it.
Watches estimate VO2 max too, often from your heart rate against your speed on walks or runs. Across 14 studies, those estimates were right on average but could be about 10 mL/kg/min out either way for one person, and estimates from resting data read about 2 high. The Apple Watch read about 6 low in studies of 30 and 40 adults, placing 14% in the right FRIEND percentile band in one, and a Garmin Forerunner 245 read about 4 to 5 low, and 6.3 low in highly trained athletes.
Follow the trend on one device over months rather than the exact number (our suggestion). A field test here and your watch may disagree by several points, and neither is a lab measurement.
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The PAR-Q+ asks seven questions. If you answer yes to any, check with your GP or a qualified exercise professional before the 12-minute or 1.5-mile run:
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The PAR-Q+ says that if you're over 45 and not used to regular vigorous to maximal exercise, you should consult a qualified exercise professional before exercising that hard, and to wait if you have a temporary illness such as a cold or fever. The NHS advises speaking to your GP first if you haven't exercised for some time, or have medical conditions or concerns. US guidelines put the risk of a heart problem at its highest when someone who is usually inactive suddenly exercises hard; the walk test is the gentler choice.
Test on a cool day, not in the heat of the day (our suggestion). In hot weather the NHS advises avoiding exercise that makes you hotter, especially between 11am and 3pm, and says there's a high risk of heat exhaustion or heatstroke "during hot weather or exercise".
Beta blockers work "by slowing down your heartbeat", so with the medicine box ticked the walk and resting heart rate tests are switched off; ask your care team before an all-out run. With the pregnancy box ticked, the calculator shows a note instead of an estimate, because pregnancy isn't the time for an all-out test and the norms don't apply (our reading). The NHS says it's not recommended to start a new vigorous activity in pregnancy, such as running, and to stop if you feel uncomfortable, too hot or unwell.
Stop and call 999 (don't drive yourself to A&E) if:
Get urgent advice from NHS 111 if:
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Stop if you feel dizzy or faint, or notice signs of heat exhaustion such as a headache, feeling sick, cramps or pale, clammy skin, and don't restart the test that day (our suggestion, from the PAR-Q+ question on dizziness and the NHS heat exhaustion signs).
See a GP if:
VO2 max is given per kilogram, so the number rises if your weight falls even when your heart and lungs haven't changed, and the walk test's formula lowers the estimate as weight rises because that's how it fitted the people it was built on (our reading). Neither says anything about your health on its own. Training is what raises your fitness, and our VO2 max guide covers how; you don't need to lose weight to do it.
If thoughts about weight or numbers are affecting how you eat or exercise, see a GP. You can also talk in confidence to an adviser from the eating disorder charity Beat by calling its helpline on 0808 801 0677.
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The formulas were built in adults and the FRIEND values start at 20. Our guide to exercise for children covers fitness at that age.
A formula built in healthy adults predicted 141% of measured fitness in 15,997 people with heart disease, and an all-out test needs your team's agreement. Ask your cardiac team about a supervised exercise test.
Check with your GP or a qualified exercise professional before an all-out test; the walk test may suit you once you have.
Pregnancy isn't the time for an all-out test, and the reference values weren't built for it (our reading), so the calculator shows a note instead of an estimate. Our exercise in pregnancy guide covers staying active.
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The heart rate tests won't fit, so the calculator switches them off. Ask your care team before an all-out run.
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Field tests and watches read low in athletes: the 12-minute run by about 6 on average in team-sport athletes, and a watch by 6.3 in highly trained runners. A lab test is the way to know.
There are no FRIEND values over 79, so the calculator doesn't show a band; Norway's HUNT study gives averages for 70 and over.
It estimates it. Even the best field tests correlate about 0.8 with measured VO2 max, and individual errors of 5 to 20 mL/kg/min are common.
Each formula was built in different people (Air Force men, adults aged 30 to 69, well-trained men) and misses in its own direction: the walk read 16 to 23% high in college students, while the 12-minute run read 6 low in athletes.
It fits mid-life adults best: it read high in college students and a little low in older adults.
It estimates it: close on average, but about 10 out for one person, and the Apple Watch read about 6 low in two studies.
An estimate isn't a diagnosis, and the reference values come from US adults who had lab tests; the 2022 update moved them down by 1.5 to 4.6. See a GP for symptoms, not for a number.
Fitness is strongly linked with a longer life, but the one long trial of training found no significant effect on deaths. The link is strong; cause and effect isn't proven.
The per-kilo number rises when weight falls without any change in your heart and lungs (our reading). Training is what raises your fitness.
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Our VO2 max guide explains how training raises it. The Norwegian 4x4 is its long-interval session, the cardio intervals workout is a shorter one, the easy cardio workout builds steady minutes, and the build-up interval walk is the gentle way in.
The Norwegian 4x4, a well-studied interval session for raising VO2 max: four 4-minute hard efforts with 3 easy minutes between, on a bike, rower or treadmill.
40 minIntermediate3 movesCardio machine, A wallA 25-minute interval session on a bike or rower: one-minute hard efforts with two minutes easy, building from 4 to 8 rounds.
25 minIntermediate1 movesCardio machineA steady 30 to 45 minute cardio session at talk-but-not-sing pace: walk, cycle, row or cross-train, counting toward weekly activity guidelines.
40 minBeginner3 movesCardio machine, A wallA 25-minute walk with short faster bouts: notice your heart and breathing speed up, then settle. A gentle way to get used to the feelings of effort.
25 minBeginner5 movesCardio machine, A wallRun as far as you can in 12 minutes on a track and enter the distance: Cooper's formula is (metres - 504.9) ÷ 44.73, so 2,400 m gives 42. If an all-out run isn't for you, a fast 1-mile walk with your heart rate at the finish works too. Both are estimates, not measurements.
It correlated 0.90 with lab VO2 max in the 115 Air Force men it came from, and about 0.78 across 26 later studies. For one person it can be well out: in 73 college athletes it read 6 low on average, and up to 20 low for some.
Compare yourself with people of your age and sex: in US lab tests the middle value was 48 for men and 38 for women in their 20s, falling to 24 and 18 in their 70s. Above the middle is above average and the top quarter is high, and the calculator shows your band. Norwegian volunteers scored higher.
Roughly: 15.3 × maximum heart rate ÷ resting heart rate. It was built in 46 well-trained men, with a standard error of about 3 mL/kg/min using a measured maximum and 5 using an age-based one; in recreational footballers it was up to about 15 out either way. The calculator switches it off if you take a medicine that slows your heart.
Walk 1 mile as fast as you can, then enter your time, your heart rate as you finish, your age, sex and weight. It was built in 343 adults aged 30 to 69 and suits people who can't or shouldn't run hard. It read 16 to 23% high in college students, so it fits mid-life adults best.
3.5 + 483 ÷ your time in minutes, which is the American College of Sports Medicine's running equation applied to your average speed. We found no study that tested this formula on its own, and those equations can read high at hard efforts, so the calculator labels the result.
Not for your exact number. Watches that use your runs were right on average across 14 studies, but could be about 10 out for one person, and the Apple Watch read about 6 low in two studies. Use one device and watch the trend.
A race time gives a performance score such as Daniels' VDOT, which mixes VO2 max with running economy, and it read lower than lab VO2 max in a small study. Use our running pace calculator for race predictions instead.
Check first if you have a heart condition, high blood pressure, chest pain, dizziness or fainting, another long-term condition, or you're over 45 and not used to hard exercise. Don't do one if you're pregnant or unwell, and stop and call 999 for chest pain or severe breathlessness. The walk test is the gentler choice.
It's given per kilo, so the number rises if your weight falls even when your heart and lungs haven't changed. Training is what raises your fitness, and you don't need to lose weight for that. If thoughts about weight are affecting how you eat or exercise, see a GP or call Beat on 0808 801 0677.
Estimates for healthy adults, not a personal prescription or a diagnosis, and clinical review of these pages is pending. Check with a GP before hard training or testing a maximum if you have a heart condition, high blood pressure, chest pain, dizziness or breathlessness when active, and stop for sharp or increasing pain. Health disclaimer.
