HOW IT WORKS
How Complete Age is calculated
How does Complete Age work?
Complete Age turns your VO2max, resting heart rate, HRV and functional tests into percentiles against norms for your age and sex, weights them, and maps the result to an age. If you add bloodwork, a PhenoAge joins the mix with a weight of its own. The result is Complete’s own number and does not diagnose anything.
What Complete Age is
Complete Age is a second age, next to your birthday. It scores how your heart, lungs, recovery and strength compare with norms for your age and sex, then turns that score into an age. An age younger than your birthday age means you score above the middle for your group, and an older one means you score below it.
Complete starts from your long-term goals. The goal under every goal is more good years, whether you train for a race, for strength or for your life, and Complete Age is the number Complete uses to follow it. Complete cannot promise you a number of years, and no app can.
Everything below describes how the method runs today, including the one input that is not switched on yet.
The inputs and their weights
Complete Age has five inputs, and each has a weight in the method. Four of them count today. Each input becomes a percentile from 1 to 99 against norms for your age bracket and sex, and Complete averages the percentiles using the weights in the table.
Consistency has a 10% slot in the method but is not counted yet. The score is a weighted average over the inputs you have, so the shares shift. With all four counted inputs present, VO2max carries about 33% and resting heart rate, HRV and functional tests carry about 22% each. When an input is missing, it drops out and the rest are re-weighted to fill the gap.
| Input | Weight | Where the number comes from | Counted today |
|---|---|---|---|
| VO2max | 30% | The most recent VO2max reading saved to your account | Yes |
| Resting heart rate | 20% | The 90-day median from one wearable: WHOOP, Oura or Apple Health | Yes |
| HRV | 20% | The 90-day median from one wearable: WHOOP, Oura or Apple Health | Yes |
| Functional tests | 20% | Your latest push-up, pull-up, dead hang and single-leg balance results | Yes |
| Training consistency | 10% | A compliance rate for your training, which the score does not receive yet | Not yet |
| Blood PhenoAge | 15%, added on top | Your latest blood panel | If you add bloodwork |
Where your VO2max comes from
VO2max is the most oxygen your body can use during hard effort. It carries the biggest weight in Complete Age: 30% in the method, about a third once the other counted inputs are in.
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[1]. 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.
Complete Age uses the most recent VO2max reading saved to your account, judged by the date of the measurement. A reading can come from a lab report, a Complete field test (the Ramp test or the Cooper 12-minute test), a value you enter yourself, or a reading synced from Apple Health.
If you have no reading yet, the Cooper 12-minute test needs a flat route or a track: run as far as you can in 12 minutes. The calculator below turns that distance into an estimate, and it works from the distance you type in.
- 1. Mandsager et al., JAMA Network Open, 2018: cardiorespiratory fitness and long-term mortality checked 18 Oct 2026
Read more
Functional tests
Functional tests carry 20% of the weight, and Complete uses four. Push-ups, pull-ups and a dead hang (hanging from a bar) are each scored against norms for your age and sex. Single-leg balance, eyes closed, is pass or fail: 10 seconds is a pass, which counts as the 75th percentile, and a fail counts as the 20th.
The input is the average of your latest result in each test you have done, so one test is enough for this input to count. Complete also records sit-to-stand, but it does not score it yet. A Cooper 12-minute test you save now counts toward VO2max.
A study of 1,104 male career firefighters, with an average age near 40, followed for 10 years found that men who could do more than 40 push-ups at the start had fewer cardiovascular events than men who could do fewer than 10[2]. The authors report an association. They say the gap may reflect other risk factors that differed between the groups, and that the result may not carry over to women, older people or people who are less active. The push-up count works as a marker in this study, and the study cannot show that push-ups cause the difference.
Resting heart rate and HRV
Resting heart rate and HRV (the small variation in time between your heartbeats) each carry 20% of the weight. A lower resting heart rate scores higher.
For each, Complete takes the 90-day median from one source and never mixes days from different devices. It uses WHOOP when the window holds at least 21 days of data. If it does not, it tries Oura with at least 14 days, then Apple Health, where Garmin and other watches’ data arrives, with at least 14 days. With fewer days than that, the input stays out of your score.
A meta-analysis of 46 studies that followed people over time found that a higher resting heart rate went with higher all-cause and cardiovascular mortality in the general population[3]. Its all-cause analysis pooled 40 studies and 1,246,203 people. The authors describe an association, and they note that a trial of a heart-rate-lowering drug in people with stable coronary artery disease found no benefit.
A second meta-analysis, of 8 studies and 21,988 people without known heart disease, found that low HRV went with a higher risk of a first cardiovascular event[4]. The authors note that low HRV may reflect disease that has not shown up yet, so the link does not show that low HRV causes events.
Blood, if you add it
Bloodwork is optional. If you add a blood panel, Complete works out a PhenoAge from your latest panel and adds it on top of the other inputs with a 15% weight. With all four counted inputs and blood present, blood carries about 14% of the total.
PhenoAge is a published method for estimating biological age from blood markers. The study that built it chose nine markers, plus chronological age, from 42 candidates, used data from the US National Health and Nutrition Examination Survey (NHANES) III and IV, and linked the result with mortality[5]. A PhenoAge younger than your age raises your score. An older one lowers it.
Panels differ, so Complete fills some gaps. When your latest panel lacks a marker, Complete uses the value from an earlier panel, and it can derive glucose from HbA1c. If CRP is missing from every panel, Complete assumes a population-average value and the app labels it as assumed.
- 5. Levine et al., Aging, 2018: an epigenetic biomarker of aging for lifespan and healthspan checked 18 Oct 2026
From score to age, and what happens when data is missing
The weighted average is your score. Complete turns it into an age with a plain rule: a year for every full 5 points above or below 50. A score from 46 to 54 gives your own age. A score of 60 gives an age 2 years younger than yours, and a score of 40 gives an age 2 years older. The rule keeps your age within 9 years of your real age in either direction, and it never goes below 18.
Complete uses the age you entered in the app, or the age from your latest assessment. Without an age, Complete cannot give you a Complete Age. If your sex is not set, Complete uses the male norms for VO2max, resting heart rate and HRV. Functional tests count once your age and sex are set.
An age appears only when there is enough to go on. Complete needs your age plus either at least half of the weight of the five inputs, or a VO2max reading with at least 30% of it. A VO2max reading alone gives a provisional age, labelled VO2MAX ONLY in the app. An age without that label needs VO2max plus any one other counted input, or resting heart rate, HRV and functional tests together, because consistency does not count yet. Two of those three without VO2max are not enough, and blood cannot unlock an age on its own. With no inputs, nothing is published.
While data is missing, the app says “Your Complete Age is still forming.” Complete works out your age again when you save a functional test or a blood panel, and when the app syncs your Apple Health or Oura recovery data. Resting heart rate and HRV use a 90-day median, so they move slowly.
Limits, and how it differs from the age on a wearable
Complete Age is not medical advice and does not diagnose anything. The studies above show links between these measures and health outcomes across groups of people. They cannot tell you what a change in your own numbers will do, and Complete cannot promise you years.
Other devices publish an age-style number of their own, built from their own inputs. Oura’s Cardiovascular Age comes from an estimate of pulse wave velocity and from changes in the shape of the pulse signal the ring reads[6]. Garmin’s Forerunner 265 manual says fitness age uses inputs such as your age, BMI, resting heart rate data and vigorous activity history[7]. WHOOP’s App Store listing describes Healthspan as a way to quantify your age and slow your Pace of Aging[8].
Complete Age combines your VO2max, functional tests you do yourself, bloodwork if you add it, and resting heart rate and HRV from your wearable: WHOOP, Oura or Apple Health, where Garmin and other watches’ data arrives. These numbers measure different things, so your Complete Age and the age on a wearable can differ.
- 6. Oura support: Cardiovascular Age checked 20 Oct 2026
- 7. Garmin Forerunner 265 manual: fitness age checked 20 Oct 2026
- 8. WHOOP on the US App Store: Healthspan and Pace of Aging checked 20 Oct 2026
Corrections
If a study or a number here is wrong or out of date, email support@ccomplete.app and we’ll correct it.
Frequently asked questions
Does training consistency count toward Complete Age?
Not yet. Consistency has a 10% slot in the method but is not counted yet. Today your Complete Age comes from VO2max, resting heart rate, HRV and functional tests, plus a PhenoAge if you add bloodwork.
Do I need a wearable for Complete Age?
No. A VO2max reading from a lab report, a Complete field test or a value you enter is enough for a provisional age, and you do the functional tests yourself. A wearable adds resting heart rate and HRV, from WHOOP, Oura or Apple Health, once it has enough days of data.
Can Complete Age be more than 9 years from my real age?
No. The rule moves your age one year for every full 5 points above or below 50, which keeps it within 9 years of your real age in either direction. It never goes below 18.
What if I have no VO2max?
You can still get an age if your resting heart rate, HRV and functional tests are all present, because an age needs at least half of the weight of the five inputs. With less than that, the app says “Your Complete Age is still forming.” A Cooper 12-minute test, a Ramp test, a lab report, a value you enter or Apple Health can add a VO2max reading.
Do I need bloodwork for Complete Age?
No. Bloodwork is optional. If you add it, Complete works out a PhenoAge from your latest panel and adds it on top with a 15% weight. Blood cannot unlock an age on its own.
Is Complete Age medical advice?
No. Complete Age is Complete’s own number and does not diagnose anything. Research on these measures shows links across groups of people and says little about any one person. Ask your doctor about your health.
Why does my Complete Age not change every day?
Complete works out your age again when you save a functional test or a blood panel, and when the app syncs your Apple Health or Oura recovery data. Resting heart rate and HRV use a 90-day median, so they move slowly, and Complete does not promise a daily change.