HRV declines substantially across adulthood — a healthy 65-year-old and a healthy 25-year-old do not look alike — which makes an age-blind "good HRV" number close to meaningless.
Heart rate variability is the variation in time between consecutive heartbeats. The specific measure used here, RMSSD, mainly reflects parasympathetic — recovery-side — autonomic activity: higher generally means more adaptive capacity, flatter means a system under load.
The bands below are drawn from Tegegne et al. (2020), a 10-second resting-ECG study of 84,772 adults in the Dutch Lifelines Cohort — one of the largest HRV reference studies published, and one of the few with enough participants to stratify cleanly by age.
Figures are milliseconds (ms) of resting RMSSD. Columns are population percentiles — the 97th means better than 97% of people that age and sex.
Here the fall with age is the whole story: the published median roughly halves from the twenties to the seventies, which is a steeper age-related decline than VO₂ max or grip strength show over the same span. The within-age spread is still wide, but age itself explains far more of the picture than it does for those two markers.
| Age | 97th | 75th | 50th | 25th |
|---|---|---|---|---|
| 20-29 | 100 | 72 | 55 | 43 |
| 30-39 | 91 | 64 | 49 | 39 |
| 40-49 | 73 | 51 | 39 | 31 |
| 50-59 | 62 | 44 | 34 | 27 |
| 60-69 | 52 | 37 | 29 | 23 |
| 70+ | 44 | 32 | 25 | 19 |
| Age | 97th | 75th | 50th | 25th |
|---|---|---|---|---|
| 20-29 | 106 | 78 | 61 | 49 |
| 30-39 | 96 | 69 | 54 | 44 |
| 40-49 | 77 | 55 | 43 | 35 |
| 50-59 | 65 | 47 | 37 | 30 |
| 60-69 | 54 | 39 | 31 | 25 |
| 70+ | 45 | 33 | 26 | 20 |
These are the exact values the Longevity Score calculator scores against, read from the engine rather than retyped, so the chart and your score cannot disagree.
The 50th-percentile row in each band is the cohort's published median. The 97th, 75th and 25th-percentile rows are interpolated from that paper's reported median and 2nd-to-98th percentile range rather than independently published quartiles — HRV's distribution is right-skewed, so the gap between the median and the top band is consistently wider than the gap between the median and the bottom band. Treat the exact quartile figures as a reasonable approximation of the published shape, not a quoted statistic.
The published cohort median falls from the mid-50s (ms) in the twenties to the mid-20s by the seventies — roughly halving over five decades. That is a far steeper age-related decline than VO₂ max or grip strength show over the same span, which is exactly why an age-blind "aim for 60+" target used elsewhere online is not a useful bar for most adults past midlife.
The study also found a modest sex difference — females trending a little higher than males at a given age — that narrows as age increases. The male and female bands below carry a small shift reflecting that finding, tapering toward the oldest band.
Absolute HRV varies enormously between individuals using different devices, electrode placements and measurement windows, so a one-off reading compared against a stranger's population table is the least informative way to use this number.
A consistent 30-to-60-day personal baseline, measured the same way each morning, is what turns HRV from a noisy single value into a genuinely useful recovery signal — a sustained fall from your own baseline says far more than where you sit on this chart.
Sleep is the single largest input, both duration and continuity. Alcohol produces one of the most reliably visible effects in all of consumer biometrics — typically a sharp same-night drop. Training load, slow-paced breathing practice and sustained psychological stress all move it over a slightly longer horizon, days to a few weeks rather than overnight.
See where you sit across all 8 dialsThe 50th-percentile row in each band is the cohort's published median. The 97th, 75th and 25th-percentile rows are interpolated from that paper's reported median and 2nd-to-98th percentile range rather than independently published quartiles — HRV's distribution is right-skewed, so the gap between the median and the top band is consistently wider than the gap between the median and the bottom band. Treat the exact quartile figures as a reasonable approximation of the published shape, not a quoted statistic.
What HRV measures and why age-blind targets mislead · How to improve HRV · The cognitive dial
Choose a question. Answers come from this site, and nothing you open is sent anywhere.
The 50th-percentile row in each band is the cohort's published median. The 97th, 75th and 25th-percentile rows are interpolated from that paper's reported median and 2nd-to-98th percentile range rather than independently published quartiles — HRV's distribution is right-skewed, so the gap between the median and the top band is consistently wider than the gap between the median and the bottom band. Treat the exact quartile figures as a reasonable approximation of the published shape, not a quoted statistic.
Chronological age counts birthdays. Biological age estimates how old your body appears to be functioning, based on measurable biomarkers. Two people born the same year can differ by a decade or more in vascular stiffness, insulin signalling or cardiorespiratory fitness. Biological age makes that gap explicit — and unlike your birthday, it can move in either direction.
Each biomarker you enter is scored against longevity-optimised reference ranges and grouped into one of eight dials. Every dial produces its own biological age, and those are combined using fixed weights into a single composite, then expressed as a Longevity Score from 0 to 100. The weighting reflects how strongly each system predicts healthspan: structural and vascular carry the most, hormonal the least.
No. The short form contains a subset of scoring inputs plus context-only fields, and you can leave any of them blank. It is not a recommendation to obtain tests. Missing values are excluded from the calculation — never treated as zero or as 'normal'. A dial with no scored data is dropped entirely and the remaining weights renormalise.
Some inputs can be measured without bloodwork. Blood pressure needs a home cuff and waist-to-height needs a tape measure. Wearable estimates vary; the floor-based sitting-rising test carries a fall risk and should only be attempted if safe.
Both terms describe what this tool does, and which one fits depends on what you are asking. "Anti-aging" is the term most people search, and loosely means anything aimed at slowing or reversing age-related decline — this tool fits that description if you score your dials and act on what you find. "Healthspan calculator" is the more precise term: healthspan is the number of years lived without serious chronic disease or disability, and that cannot be measured directly, so this tool scores eight systems that each function as an early-warning proxy for it. Either way, the method is the same: real biomarkers, published thresholds, no vanity-metric framing.
Several popular tools ask only about habits — exercise days, sleep hours, smoking, diet quality — and return a single precise-looking age. We looked at the research behind that approach and chose not to build it. Published studies do show real, individually-measured links between specific habits and epigenetic age acceleration, but those effect sizes come from different study populations, different DNA-methylation clocks and different measurement units. Adding them together into one number is not something the underlying research actually supports — it produces a precise-looking result built on an imprecise method. Our dials use direct physiological measurements instead: a real blood pressure reading, a real VO₂ max, a real ApoB value. Several dials score from home-measurable data alone with no quiz-guessing involved — see what you can measure without a blood test, above.
Standard reference ranges describe what is common in a general population, which now includes a great deal of metabolic dysfunction. They are tuned to flag disease, not to identify what is optimal for a long healthspan. A fasting insulin of 20 µIU/mL sits inside most labs' normal range and is strongly associated with insulin resistance. This tool uses longevity-optimised thresholds instead, so a flag here means room for optimisation — not a diagnosis.
For understanding a single result, do — a frontier chat model is genuinely good at that, often clearer than most medical sites, and it handles markers no fixed tool covers. The limitation is different from the one most people assume. A language model produces a plausible response rather than a computed one, so the same panel can score differently on different days. That is fine when exploring an idea and disqualifying when measuring change, because you cannot tell how much of a difference is you and how much is the method. Use both: a chat model to understand, a fixed instrument to track.
Biomarker values, assessment history and visit-preparation drafts are stored in your browser. The visit draft is separate from assessment exports and share links; copying or printing it can leave a copy outside the browser. There are no user accounts or third-party tracking. We keep anonymous usage totals on our own server, such as how many people reached a results screen on a given day; browsers sending Do Not Track or Global Privacy Control are not counted. Optional lab-report upload and AI coach features send data to Anthropic. Optional retest reminders send an email address, date and reminder label to our service and email provider. See our privacy policy for details.