Apple Health Age Is A New Metric by Apple and Here’s How They Calculate Your Biological Age

Biological age is everywhere. It is the new “Sleep Score” everyone is trying to ace. And you know who validated it? Apple. Yes, while Apple spent most of its Sep 9 keynote talking about chips and cameras, but at some point, it announced something that will change a lot of things about the way we perceive our Apple Watch data. The new feature, which Apple calls Health Age, allows people to evaluate how fast or slow their bodies are aging compared to what their birthday says it should!

The only thing I ever wondered about when looking at my VO2 max numbers year after year is how to interpret those numbers. The new Health Age feature from Apple is designed specifically to answer this question. It uses all the metrics your Apple Watch collects and transforms those into just one metric that makes sense. Here is everything I found out about the new Apple Health Age feature and how it compares to the similar features from Oura, WHOOP and Garmin.

What Is Apple Health Age?

Health Age will appear in a new Longevity tab in the redesigned Health app. It isn’t a separate app or a new watch face. Once the update rolls out, you’ll find it directly in the Health app.

The idea is simple even if the science behind it isn’t. Your chronological age can be considered a fixed number that depends only on your birthday and cannot be altered even if the Botox makes you look 10 years younger. Health Age stands for the estimation made by Apple concerning how well your body works compared to your peers based on your real data that was collected from the Apple Watch. According to Apple, the concept relies on top scientific knowledge and uses data from the Watch, iPhone, AirPods and lab tests if you choose to add them.

So if you are 42 years old but have the same physical abilities as those of a person aged 35, then this information will be conveyed to you by the Health Age feature.

Speaking of blood work, there are 2 options- if you are in the US, you can request a blood panel from Quest at $119 with over 50 biomarkers and if you’re outside the US, you can upload your existing blood work into the app. Very similar to WHOOP Advanced Labs and UltraHuman Blood Vision.

Biological Age vs Chronological Age: What’s the Actual Difference

Chronological age is easy. It’s just how many birthdays you’ve had. When two people were born on the same day, they have the same chronological age, regardless of their experiences.

Biological age is more complicated but more valuable. This is an attempt to assess the state of your body currently through factors like cardiovascular fitness, sleep, recovery and sometimes even blood tests. Two people who are both 45 years old might have completely different biological ages based on their lifestyle.

Something to make clear on this front is that biological age, regardless of whether it is measured by Apple, a blood test, or an app on your phone, is an estimate. It is not a diagnosis and not a medical evaluation of your lifespan. Remember this when you freak out about a score on your phone.

How Does Apple Actually Calculate Health Age?

Apple has confirmed the core inputs and none of them are new metrics, they’re just being combined in a new way.

VO2 max: VO2 max is an indicator of your cardiorespiratory fitness, which is basically how efficiently your body utilizes oxygen during physical activity. VO2 max has been tracked for ages via the Cardio Fitness feature by Apple and is having tremendous importance in the Health Age calculation process. What is even more interesting, the same metric is the one that has been named the strongest predictor of long term health outcomes among all metrics available from wearable devices. Apple also has a new way of testing VO2 Max, which is truly revolutionary.

Resting heart rate (RHR): The resting heart rate has been found to be an indicator of cardiovascular fitness and recovery over a long period of time. It is not about the single-day value, but the trend of your values over time.

Heart rate variability (HRV): HRV refers to variation between beats and it is one of the best available indicators of stress and recovery levels. With the new Health Sensing System, Apple Watch Series 12 and Ultra 4 now track HRV every 5 minutes, 24 times more than the previous versions. Health Age works with any Apple Watch with watchOS 27, though.

Sleep Data: Duration, consistency and how well your sleep habits stick over a couple of weeks, not just one-off night.

Optional lab test: This was the thing that I really appreciated Apple taking up. You can add A1c and LDL cholesterol to feed into your Health Age. Apple has partnered with Quest Diagnostics for US users who would like to order their at-home lab panel that includes more than 50 biomarkers for $119. This isn’t necessary for a Health Age score, but helps fill in the blanks that your Watch cannot measure.

Health Age works exclusively on the Apple Watch and will be compatible with the following: Apple Watch Series 9 and above, Apple Watch SE 3 and above and Apple Watch Ultra 2 and above with watchOS 27, releasing September 14. You won’t have to upgrade to the Series 12 and Ultra 4 specifically for a Health Age assessment, thankfully.

Apple Health Age vs Other Wearable Age Scores

Brand	Score Name	Data Window	Core Inputs	Notes
Apple Watch	Health Age	Ongoing, updates as new data comes in	VO2 max, resting heart rate, HRV, sleep patterns	Optional lab tests can be added
WHOOP 5.0 / MG	WHOOP Age (Healthspan)	6 months, with a faster-moving Pace of Aging pulling from the last 30 days	Sleep consistency, total sleep time, time in HR zones 1–3, time in HR zones 4–5, strength training time, daily steps, VO2 max, resting heart rate, lean body mass	WHOOP Advanced Labs offers inputting blood work
Oura Ring	Cardiovascular Age	Rolling, needs 14 nights of data to generate first	Pulse wave velocity, estimated from PPG signal shape as a proxy for arterial stiffness	Single-signal score, not a composite. Oura explicitly ties this to heart and artery health specifically, not overall fitness
Garmin	Fitness Age	Rolling average	VO2 max plus, on newer devices, activity intensity (vigorous days and minutes), resting heart rate, and body fat percentage or BMI	Older Garmin watches ran this on VO2 max alone. Needs a Garmin Index smart scale for body fat %, otherwise falls back to BMI

Why Apple Is Moving Toward Longevity Tracking

Wearables started off with a decade of metrics. Steps, calories, workouts tracked. This stage is pretty much over and there isn’t anything special about a modern watch that can count steps anymore.

Today we are seeing a new focus on analysis. Scores like readiness, recovery and longevity try to provide an answer to a more complicated question than just “how much did you exercise today.” They try to give you insight on whether your routine is effective and what to do if not.

The new Longevity tab on Apple Health uses the heart health, sleep, mental wellbeing, movement, metabolic health, hearing and nutrition, based on data collected from the Watch, iPhone, AirPods, health records and other third-party apps and devices. There is a lot more data to use here compared to wrist-based sensors.

Can Apple Watch Really Measure Your Biological Age?

Short answer: no, it cannot actually be considered an effective method for clinical use. However, there is a much more interesting answer here. What the Apple Watch is good at doing is spotting trends. It can indicate to the user that his/her resting heart rate increased during the last three months, or that the VO2 max increased after the person began running again. Those are very useful indicators.

What it cannot do is evaluate cellular aging, serve as a replacement for a regular blood test or epigenetic clock, or predict our life span. Researchers who study wearables’ scores on aging have come to several key conclusions which include the fact that the information is always provided by those people who could afford the expensive device, self-reported health data might not always be accurate, and most consumer “aging” scores are nothing more than indicators of cardiovascular fitness in disguise. 

The inclusion of lab data option is a very intelligent move exactly because of that. Consider the Health Age to be similar to all other health scores that might appear on your smartphone. A good way to evaluate your next steps to a healthy lifestyle, not a number to be taken as gospel.

When Can You Actually Use It

watchOS 27 and the new Health app will debut on September 14, before the availability of the new devices on September 18. The new Health Age feature will support only English at launch. 

To use Health Age, an Apple Watch with watchOS 27 is required, as well as the new Health app on an Apple Intelligence compatible iPhone.

Wrap Up

The wearable war is no longer about who is packing the most sensors, but rather who can interpret the data better.

Here, Apple holds an advantage. Health Age comes from a platform where there are hundreds of millions of people and years of data on them. This is something its competitors cannot replicate easily.

It might boil down to this: the war on wearables is whoever can interpret your health data best. And Apple may have just won solely on the basis of their market share.