VO2MAX
The best VO2max apps in 2026
What is the best VO2max app?
In our ranking the best VO2max app is Complete. Complete is our own app. We wouldn’t build it if we didn’t think it was the best, we train with it ourselves, and we work every day to make it better. VO2max is the most oxygen your body can use in hard exercise; Complete gives no passive estimate from daily wear, so for that you need a wearable, and Complete reads Apple Watch through Apple Health.
Complete is our own app, and we rank it first
Complete is our own app. We wouldn’t build it if we didn’t think it was the best, we train with it ourselves, and we work every day to make it better. It is first on this list. The same five criteria apply to every app, and the next section prints them.
The first criterion favors Complete: it asks where a VO2max reading can come from, and Complete takes a test, a value you type in or a reading from Apple Health. A reader who ranks by a passive estimate would put the watches first.
Every fact about another app comes from that company’s own page, read on 20 October 2026, and each section links its page. We tested no device. Check the company’s site for prices.
How we ranked them
VO2max is the most oxygen your body can use during hard exercise. We asked every app the same five questions.
| Criterion | What we check |
|---|---|
| 1. Where a reading comes from | A sensor estimate, a test you take, a value you type in, or several |
| 2. What you need to own | The device the page names |
| 3. Method on the page | How much the page says about how the number is made |
| 4. Platforms | Where the page says it runs |
| 5. Price | A price only when the page shows one |
How the order works
Criterion 1 sets two levels. At level 1, the page describes more than one way to get a number, such as a test you take or a value you type in. At level 2, it describes one way: the watch’s own sensors or a resting test. Inside level 1, we compare the kinds of source each page names. Inside level 2, the order is our judgment of how much the page says about how the number is made and where it stops. Neighbors are close calls.
Criterion 3 orders the apps inside level 2. Criteria 2, 4 and 5 describe each app and do not affect the order. We do not rank which estimate is the most accurate, because we have no head-to-head evidence, and we do not rank convenience, where a watch that estimates on its own does well. A feature missing from a page we read may still exist.
1. Complete: a test, a typed value or Apple Health
Complete starts from your long-term goals, and VO2max is one of the numbers it follows. It takes a reading from a lab test you import, a Complete field test (the Cooper 12-minute test, where you run as far as you can in 12 minutes, or the Ramp test), a value you type in, or a reading synced from Apple Health, where Apple Watch data arrives. It is first because it takes four kinds of source.
Complete gives no passive estimate from daily wear. If you want an estimate that updates as you train, you need a wearable, and you can type any watch’s number into Complete. Our free web calculator estimates VO2max from a Cooper 12-minute distance.
Complete Age is one age number for your body: it compares your VO2max, resting heart rate, HRV (the small variation in time between heartbeats) and functional tests with norms for your age and sex. The nominal weights are 30% for VO2max and 20% each for the other three inputs; the score renormalizes these weights across available inputs. Training consistency has a nominal 10% slot but is not counted yet, so with those four inputs and no bloodwork, VO2max carries about a third of the score. A VO2max reading alone gives a provisional age, labelled VO2MAX ONLY.
Complete is for iPhone only (iOS 17+) and free to download, and logging and sharing your workouts on it stay free. Complete Age is not medical advice, and we make no accuracy claim for any VO2max number in Complete.
2. Oura: a first estimate, a walking test or a typed number
Oura’s Cardio Capacity is an age-adjusted estimate of your VO2max. The first reading comes from your age, sex, height and weight, and Oura calls it an estimate based on population averages[1]. The app then prompts a six-minute walking test that uses distance and heart rate[1]. You can also type in a value from a lab test or a trusted source, such as another wearable[1]. It is second because the page offers a test and accepts a value from another source.
- 1. Oura Help: Cardio Capacity (VO2 Max) checked 20 Oct 2026
3. WHOOP: a passive estimate, sharpened by a GPS run
WHOOP says it estimates VO2max through a three-tier proprietary algorithm: a passive model, a GPS-augmented model and a calibrated estimate[2]. It updates weekly, needs at least 14 recoveries in the last 21 days, and gets more precise with a GPS-tracked run of 15 minutes or more[2]. Members with a lab-tested VO2max can enter it by hand, using the date of the assessment[2]. It is third because the page we read names a lab score you type in, and not a value from another wearable.
- 2. WHOOP Locker: VO2 Max estimate checked 20 Oct 2026
4. Apple Watch: Cardio Fitness from outdoor workouts
Apple’s support page says cardio fitness is a measurement of your VO2max. Apple Watch Series 3 or later estimates it from heart and motion sensor data during outdoor walk, run and hiking workouts, and indoor workouts do not count[3]. It also uses your age, sex, weight, height and medications that might affect your heart rate, and it supports a range of 14 to 65 mL/kg/min[3]. Apple says conditions or medications that limit your heart rate might cause an overestimate[3]. It leads level 2 because the page states the sensors, inputs, range and limits.
- 3. Apple Support: Track your cardio fitness levels checked 20 Oct 2026
5. Polar: a resting fitness test on the watch
Polar’s manual for the Unite watch describes the Polar Fitness Test, which estimates your aerobic fitness at rest from wrist-based heart rate[4]. The result, Polar OwnIndex, is comparable to VO2max, and your training background, heart rate, HRV at rest, sex, age, height and weight all influence it[4]. The test is developed for healthy adults[4]. We read the manual for one watch, so check your model. It sits fifth because the page lists the inputs and the test conditions but prints no supported measurement range.
- 4. Polar Unite user manual: Fitness Test with wrist-based heart rate checked 20 Oct 2026
6. Garmin: a run-based estimate with no test
Garmin’s page says the Garmin Human Performance Lab engine in your watch estimates VO2max during your run, placing your pace in the context of how hard your body is working[5]. You run as you normally would, without a special fitness test[5]. Garmin says some recent watches, paired with a compatible smartphone, recognize hot, humid or high-altitude runs[5]. The page explains the principle and its heat and altitude adjustment, but says more about the method than COROS’s article, but lists no profile inputs such as age or weight and prints no supported range, so it sits sixth.
- 5. Garmin Technology: VO2 max checked 20 Oct 2026
7. COROS: a running estimate from heart rate and pace
COROS’s help article says that as you record more outdoor runs, COROS estimates your VO2max and adjusts it over time based on changes in heart rate and pace[6]. It lists age, gender, weight, heart rate and Training Status as factors, and you read the value in the COROS app or on the watch[6]. The article gives the method in two sentences and prints no supported range or limits, so it sits seventh.
- 6. COROS Help: Running VO2 Max checked 20 Oct 2026
The ranking at a glance
Each row for another app repeats the company’s page as read on 20 October 2026. Not stated means the page gave no price or platform.
| App | Where a reading comes from | You need | Platforms | Price (checked 2026-10-20) |
|---|---|---|---|---|
| 1. Complete | A lab test, a Cooper or Ramp test, a typed value, or Apple Health | An iPhone | iPhone only (iOS 17+) | From App Store launch, $99.99 a year with a 7-day free trial. |
| 2. Oura | A profile estimate, a walking test, or a typed value | A Gen3 or later ring with membership | iOS and Android | Not stated |
| 3. WHOOP | A passive and GPS-run estimate, or a typed lab score | A WHOOP membership (the page names no device) | Not stated | Not stated |
| 4. Apple Watch | Sensors during outdoor walk, run and hiking workouts | Apple Watch Series 3 or later | Health app on iPhone or iPad | Not stated |
| 5. Polar | A resting test with wrist-based heart rate | A Polar watch (Unite manual) | Syncs with the Flow app | Not stated |
| 6. Garmin | Pace and effort during runs | A Garmin watch | Not stated | Not stated |
| 7. COROS | Heart rate and pace on outdoor runs | A COROS watch | COROS app and watch | Not stated |
- 7. Oura Help: Cardio Capacity (VO2 Max) checked 20 Oct 2026
- 8. WHOOP Locker: VO2 Max estimate checked 20 Oct 2026
- 9. Apple Support: Track your cardio fitness levels checked 20 Oct 2026
- 10. Polar Unite user manual: Fitness Test with wrist-based heart rate checked 20 Oct 2026
- 11. Garmin Technology: VO2 max checked 20 Oct 2026
- 12. COROS Help: Running VO2 Max checked 20 Oct 2026
How to pick for your goals
Start from your goal. For a number that updates on its own, choose a wearable: Apple Watch, Garmin and COROS estimate from your workouts, and WHOOP from passive data and GPS runs. Polar asks you to take a resting test, and Oura refines a first estimate with a walking test.
To keep VO2max next to your other fitness numbers over the years, Complete takes a test, a typed value or a reading from Apple Health and uses it inside Complete Age. A lab result can go into Complete, Oura or WHOOP, according to their pages.
With no wearable, a test you take is the way in, such as the Cooper 12-minute test or the Ramp test in Complete, or our free calculator. Compare a number with earlier readings from the same app or test, because one company’s estimate is not the same measurement as another’s.
What a VO2max number cannot tell you
A VO2max figure from an app is an estimate unless it comes from a lab test. Apple says conditions or medications that limit your heart rate might cause an overestimate[13], and Oura says its walking test is not as accurate as a lab test and may not give a precise estimate for high-performing athletes[14].
A study of 122,007 adults who took a treadmill test found that higher cardiorespiratory fitness went with lower mortality, with no upper limit of benefit observed[15]. The study followed people through past records for a median of 8.4 years, and it estimated fitness from treadmill performance. It shows an association and cannot show cause.
A VO2max number in any app is not medical advice. If a number worries you, ask your doctor.
- 13. Apple Support: Track your cardio fitness levels checked 20 Oct 2026
- 14. Oura Help: Cardio Capacity (VO2 Max) checked 20 Oct 2026
- 15. Mandsager et al., JAMA Network Open, 2018: cardiorespiratory fitness and long-term mortality checked 18 Oct 2026
Corrections
If a page above has changed or we got a fact wrong, email support@ccomplete.app and we’ll correct it. If you make a VO2max app and describe how your number is made, send us the link and we will read it.
Frequently asked questions
Which VO2max app is the most accurate?
We did not rank accuracy, because we have no head-to-head evidence. Oura says its walking test is not as accurate as a lab test, and Apple says some conditions or medications can cause an overestimate. Each company’s page describes its own method, and we tested none of them.
Does Complete estimate VO2max from my watch?
No. Complete gives no passive estimate from your watch. It takes a lab test you import, a Cooper or Ramp field test, a value you type in, or a reading synced from Apple Health, where Apple Watch data arrives. You can type in a number from a Garmin, COROS or Polar watch.
Do I need a watch to get a VO2max number?
Not for Complete, which offers the Cooper 12-minute test and the Ramp test, and our free web calculator works from a Cooper distance. Oura’s walking test needs a Gen3 or later ring. Apple Watch, Garmin, COROS and WHOOP estimate from sensors.
Can I enter a lab VO2max result?
Yes. Complete, Oura and WHOOP say so. Complete takes a lab test you import or a value you type in. Oura and WHOOP say you can add a lab value by hand, and WHOOP asks for the date of the assessment.
How much does VO2max count in Complete Age?
VO2max has a nominal 30% weight, while resting heart rate, HRV and functional tests have nominal 20% weights each; the score renormalizes these weights over available inputs. Training consistency has a nominal 10% slot but is not counted yet, so with the four core inputs and no bloodwork, VO2max makes up about a third of the score.
Is a VO2max number medical advice?
No. A VO2max number in any app is not medical advice. Ask your doctor about your health.
Can you trust a ranking from a company that makes one of the apps?
Complete is our own app. We wouldn’t build it if we didn’t think it was the best, we train with it ourselves, and we work every day to make it better. We rank it first, we say that the first criterion favors it, and we link the company page behind each fact about another app. If you find an error, email support@ccomplete.app.