7 Best Apple Watch Apps for Pace of Aging, Ranked

Body Insights is our best overall Pace of Aging app for Apple Watch. It applies studies on steps and death rates to an age-based pace calculation. The Gompertz model turns the research into a Pace of Aging reading. Its Trends card shows that reading with six months of step history. SuperAge, My Bio Age, Cortisol+, and Nuvo also list Pace of Aging. Each app uses its own method and data.

Two more Apple Watch apps show a related age result. RelaxWatch focuses on Body Age. FixMyAge lists DunedinPACE on iPhone and has separate Watch tools for protocol tracking. These results use different methods. This roundup compares listed features, not accuracy.

The Pace of Aging calculation guide explains the studies and model behind Body Insights. We own and publish Body Insights. We have a direct interest in recommending it.

Our picks

1. Body Insights: Best research-based Pace of Aging

Body Insights uses published studies on daily steps and death rates to calculate Pace of Aging. It compares your recent Apple Health step pattern with a target for your age. Then the Gompertz model turns the research into a pace reading. The Trends card shows it beside six months of step history.

The calculation draws on a JAMA study of US adults and a meta-analysis of 15 study groups. Both link steps with deaths across groups. A 2021 paper by Pang and Hanley explains how the Gompertz model turns a death-rate ratio into an age comparison. Read their paper.

This age conversion has assumptions. It assumes the relative difference in death rates stays similar across ages. It also assumes that death rates rise in a Gompertz pattern. These papers support the research and method, but they do not test the Body Insights score. We own Body Insights. We recommend it for its research basis and six-month trend.

Our verdict: Start with Body Insights for a Pace of Aging reading grounded in peer-reviewed mortality research, with a six-month trend beside it.

2. SuperAge: Best for biomarker comparisons

SuperAge's App Store listing names a Pace of Aging feature. It says the app compares biomarkers with expected values for age. The listing also describes Apple Health and age, fitness, and recovery views. SuperAge runs on iPhone and Apple Watch.

The listing does not name every biomarker in the pace result. SuperAge uses a different health model from Body Insights' step and death-rate research.

Our verdict: Pick SuperAge for an age comparison built around biomarkers.

3. My Bio Age: Best for longer rolling trends

My Bio Age names a Pace of Aging result. Its listing describes 12-week comparisons and a rolling average over 24 weeks. It also lists a 12-metric MyBioAge Index and on-device processing. The app runs on iPhone and Apple Watch.

The longer view may suit someone who wants a multi-month comparison. My Bio Age and Body Insights use different methods. Their numbers are not interchangeable. My Bio Age requires iOS 26 or later and 2 GB of free space for its AI features.

Our verdict: Choose My Bio Age for a longer rolling view and a broader age index.

4. Cortisol+: Best for recovery-based estimates

Cortisol+ lists Pace of Aging and Bio Age results based on recovery data. Its listing names HRV, heart rate, sleep, and activity as inputs. The app has Apple Watch companion features.

The name can sound like a blood test. The developer says the app does not measure cortisol in blood. Its age and pace results are for wellness and information. The app uses different inputs from Body Insights' research-based pace calculation.

Our verdict: Pick Cortisol+ for an HRV and recovery-focused view. The app does not measure blood cortisol.

5. Nuvo: Best for a broader longevity view

Nuvo names Pace of Aging among its Apple Health features. It works on iPhone, Apple Watch, and iPad. The listing also describes optional blood-report inputs and longevity coaching.

Nuvo puts the pace result inside a wider product. The listing places full access to these features behind a paid subscription or trial. Its output uses a broader set of inputs and a different method from Body Insights' published mortality model.

Our verdict: Pick Nuvo if you want a wider longevity app with coaching.

6. RelaxWatch: Best for a Watch-based Body Age view

RelaxWatch describes a Body Age estimate from HRV, heart rate, sleep, and activity. Its Watch app includes a Body Age view. The listing's version notes describe an aging-pace layout among those age details.

This is a related age view. It uses recovery signals and has a Body Age display on the Watch. It does not use the same peer-reviewed step-count mortality research and Gompertz model as Body Insights.

Our verdict: Choose RelaxWatch for a recovery-led Body Age view on the Watch.

7. FixMyAge: Best for DunedinPACE detail on iPhone

FixMyAge lists Pace of Aging (DunedinPACE) in its iPhone Overview. Its Apple Watch app has protocol logging, a progress ring, and a complication. The DunedinPACE detail stays on iPhone.

The split matters if you expect to read the pace result on your Watch. FixMyAge's DunedinPACE detail is on iPhone. The Watch app supports the related protocol, but does not show that detail.

Our verdict: Consider FixMyAge for its DunedinPACE view on iPhone and protocol progress on Watch.

These pace measures use different scales

Body Insights applies research on steps and death rates through a target for your age and the Gompertz model. SuperAge and Nuvo describe age comparisons that use biomarkers or blood reports. My Bio Age has a wider age index. Cortisol+ and RelaxWatch use recovery data. FixMyAge lists DunedinPACE on iPhone. Each app uses its own data and model, so its pace value may mean something different.

Compare the data each app reads, where it shows the result, and how much history it gives you. App Store descriptions list product features. They do not provide independent tests of each app's age or pace calculation.

Why Body Insights wins this list

Body Insights earns our top spot because its Pace of Aging uses published studies on steps and death rates. It compares step records with a target for your age. The Gompertz model turns the research into a pace reading. The six-month trail shows how that reading moves with your step pattern. The app does not measure biological age.

SuperAge, My Bio Age, Cortisol+, and Nuvo suit people who want biomarkers, several age measures, recovery inputs, or a broader longevity plan. RelaxWatch and FixMyAge offer related results. None of the seven listings shows that an app measures a person's biological aging speed.

Related reading

• How Body Insights calculates Pace of Aging
• Best fitness age apps for Apple Watch
• How fast am I aging? Read your Apple Watch trend

Open the Body Insights App Store listing to see its Watch and iPhone features. Then read the Pace of Aging guide to see how the studies, the age-based target, and the Gompertz model shape its reading.