Sleep is upstream of most of the other dials. It raises blood pressure and resting heart rate, lowers HRV, impairs glucose handling, raises inflammatory markers and suppresses testosterone — which means fixing it often explains several otherwise puzzling results at once.
Target7–9 hrs
The longevity-optimised range used by the cognitive dial. See what sleep measures for the reasoning.
What to expect, and when
Alertness and mood improve within days. Metabolic and cardiovascular markers follow over two to four weeks. Sleep debt accumulates faster than it repays, so one long weekend does not clear a working week.
What works, in order of leverage
1. Fix your wake time, not your bedtime
A constant wake time anchors the circadian rhythm regardless of when sleep began, and sleep onset follows it. The single highest-yield change for most people, and the one most often done backwards.
2. Get outside within an hour of waking
Ten to twenty minutes of daylight advances the rhythm and makes sleep onset earlier the same night. Indoor light is an order of magnitude too dim to do this.
3. Stop drinking alcohol in the evening
It shortens sleep onset and degrades everything after it, reliably suppressing REM and fragmenting the second half of the night. Any wearable will show you this on your own data.
4. Move caffeine earlier
A six-hour half-life means an afternoon coffee is substantially present at bedtime. Timing matters more than total intake.
5. Cool the room
Core temperature has to fall for sleep to consolidate. More reliable than most supplements and free.
6. Get screened for apnoea if sleep is unrefreshing
Snoring, witnessed pauses, or exhaustion despite adequate duration all warrant proper assessment. No amount of sleep hygiene fixes an obstructed airway.
Supporting supplements
Magnesium L-threonate — 1.5–2g/dayevidence B
Only form shown to cross blood-brain barrier effectively. Improves synaptic density and working memory in RCTs.
Evidence tiers: A = consistent human trial support, B = mixed or mechanistic, C = early. Supplements support the changes above; they do not replace them.
What does not work
Worth knowing before spending effort on it.
Catching up at weekends
Partially restores alertness and does not restore metabolic function. It also shifts the rhythm later, which makes Monday worse.
Treating wearable sleep stages as accurate
Consumer devices are reasonable at duration and timing and unreliable at stage classification. Act on the parts they measure well.
Alcohol as a sleep aid
It is a sedative, not a sleep aid. Sedation is not sleep, and the rebound in the second half of the night is the cost.
Melatonin at high doses for ordinary insomnia
Melatonin is a timing signal, not a sedative. It helps circadian problems such as jet lag at doses far lower than those commonly sold; for most insomnia it does very little.
More time in bed
Spending longer in bed to get more sleep usually fragments it. Compressing time in bed is the counterintuitive basis of the most effective insomnia treatment there is.
When to involve a clinician
Persistent insomnia is treatable, and cognitive behavioural therapy for insomnia outperforms medication for long-term outcomes. Loud snoring, witnessed breathing pauses, or sleepiness despite adequate duration should be assessed for sleep apnoea.
Not medical advice. These are longevity-optimised reference ranges, which are deliberately stricter than standard clinical "normal" values. A value outside them does not mean you have a disease. Speak to a qualified healthcare professional before changing medication, supplements or training. Full disclaimer.
Ask Us
Choose a question. Answers come from this site, and nothing you open is sent anywhere.
What is biological age?
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.
How is the Longevity Score calculated?
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.
Do I need all 53 biomarkers?
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.
What can I measure without a blood test?
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.
Is this an anti-aging calculator? Is it a healthspan calculator?
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.
Why don't you have a quick quiz that skips biomarkers entirely?
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.
Why are your 'optimal' ranges stricter than my lab's normal range?
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.
Why not just upload my labs to ChatGPT?
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.
Is my health data private?
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.
Is this a medical diagnosis?
No. It is an educational and personal-tracking tool. The estimates are not clinically validated and must not replace evaluation by a qualified healthcare professional. If a result concerns you — particularly kidney markers, blood pressure or ApoB — take it to a doctor rather than acting on it alone.