How Prime Age Is Calculated — Full Methodology
Version 2026-08-26. Effective 26 August 2026.
Prime Age is an educational estimate of the age your daily habits suggest. It is produced by adding up twelve lifestyle answers you give yourself, applying a fixed published weight to each, and adding the total to the age you entered. Nothing is measured, no sample is taken, and no data about your body is read from any device. It is not a medical test, not a diagnosis, and not medical advice.
This page exists so that the number is not a black box. Every question, every weight and every rule below is the same one the calculator uses — on agegen.ai/prime-age and in the Telegram app alike.
The arithmetic, in full
- You enter your age.
- You answer twelve questions. Each answer carries a weight in years — some negative, some positive — listed in the table below.
- The twelve weights are added together. That sum is your delta.
- The delta is limited to the range −12 to +15 years. Answering every question in the best way sums to −13, and in the worst way to +21; both are clamped, so no single profile can move the number further than that range.
- Prime Age = your age + delta, rounded to the nearest whole year, and never below 18.
There is no hidden term, no adjustment for sex, country or anything you did not type, and no random component. The same answers always produce the same number.
All twelve questions and every weight
A negative number lowers your Prime Age; a positive number raises it.
| Answer | Years | |
|---|---|---|
| 😴 1. How much sleep do you get most nights? | ||
| 7–8 hours | -1 | |
| 6–7 or 8–9 hours | 0 | |
| Under 6 hours | +1.5 | |
| ⏰ 2. Do you go to bed and wake up at roughly the same time? | ||
| Within ~30 min, most days | -1 | |
| Weekends drift 1–2 hours | +0.5 | |
| All over the place | +1.5 | |
| 🏃 3. Cardio (brisk walking, cycling, zone-2) per week? | ||
| 150+ minutes | -2 | |
| 60–150 minutes | -0.5 | |
| Under 60 minutes | +1.5 | |
| 🏋️ 4. Strength training sessions per week? | ||
| 2 or more | -2 | |
| 1 | -0.5 | |
| None | +1.5 | |
| 🥩 5. How often does a meal include a solid protein source? | ||
| Almost every meal | -1 | |
| About half of them | 0 | |
| I rarely think about it | +1 | |
| 🥦 6. Vegetables, fruit and fiber per day? | ||
| 5+ servings | -1 | |
| 2–4 servings | 0 | |
| 0–1 serving | +1 | |
| 🍷 7. Alcoholic drinks in a typical week? | ||
| 0–1 | -1 | |
| 2–7 | +0.5 | |
| 8 or more | +2 | |
| 🚬 8. Smoking or vaping? | ||
| Never | -1 | |
| Quit | +0.5 | |
| Currently | +4 | |
| 🪑 9. Hours of sitting on a normal day? | ||
| Under 6, or frequent breaks | -0.5 | |
| 6–9 hours | +0.5 | |
| 10+ hours | +1.5 | |
| 🧘 10. How does stress usually feel? | ||
| I have a daily practice that works | -1 | |
| Manageable, most weeks | 0 | |
| Chronically overwhelmed | +2 | |
| 🤝 11. Close relationships you can actually lean on? | ||
| Several, and we talk often | -1 | |
| A few, on and off | 0 | |
| Honestly — isolated lately | +1.5 | |
| 📏 12. Your waistline over the last 5 years? | ||
| Stable | -0.5 | |
| Slowly growing | +1 | |
| Grew significantly | +2 | |
Why these twelve
They are the lifestyle factors most consistently associated with healthy lifespan in population research: sleep duration and regularity, aerobic and resistance exercise, protein and fibre intake, alcohol, tobacco, sedentary time, chronic stress, social connection, and central adiposity. We chose factors that a person can answer honestly in ten seconds and can actually change — which is why the list contains no genetics, no family history and no laboratory value.
How the weights were chosen — and what that means
The weights are editorial, conservative and directional. They are not derived from a published statistical model, and Prime Age is not a validated instrument. We say this plainly because the alternative — implying a precision the method does not have — is the thing that makes self-assessment tools misleading.
What the weights do encode is the relative ordering the evidence supports: smoking carries the heaviest single penalty on the list; regular exercise and adequate sleep carry the largest benefits; a factor with a weaker or noisier association carries a smaller weight. The whole range is deliberately narrow — twenty-seven years wide across every possible profile — so that no answer can produce an alarming or flattering number.
Read the direction, not the digit. A Prime Age three years below your age means your current habits point the right way. It does not mean your body is three years younger, and no number on this site should ever be read that way.
The daily check-in, in the app
In the Telegram app the same twelve levers are re-answered over time. Two questions are asked every day — how you slept, and whether you moved — and a third rotates through the remaining levers across the week, so all twelve stay current without ever putting more than three questions on the screen. Smoking is asked once a month.
Your Prime Age on any given day is calculated from the most recent answer for each of the twelve levers, using exactly the arithmetic above. An answer stays in force until you replace it.
Two levers are worked out rather than asked
Weekly exercise volume. A single day cannot answer a question about a week, so the daily movement answer feeds a rolling seven-day window: a walk counts as 25 minutes, a cardio session as 40, a strength session as 15 of incidental movement plus one session. The window is then scored on the same thresholds the questionnaire uses — 150 and 60 minutes a week for cardio, two and one sessions for strength.
Sleep regularity. This one is never asked in the app. The time of day at which you answer the first question is your wake time, so the spread of those times across the week is the answer. It is computed as a circular spread, which is why answering at 23:50 one night and 00:10 the next counts as twenty minutes apart and not as twenty-four hours. A spread under 30 minutes scores −1, under two hours +0.5, wider +1.5 — the same three bands the question offers. We use this instead of asking because it needs no permission, no health app and no extra tap.
Signal
Signal is the share of the twelve levers whose current answer came from a measurement rather than from something you told us. Everything you type is a self-report, and self-reports are a starting point rather than a truth. Signal exists to say so honestly and visibly, on the same screen as the number.
What Prime Age is not
- Not a biological-age test. Biological-age estimates are built from biomarkers — methylation, blood chemistry, imaging. This uses none of them, because it collects none of them.
- Not a diagnosis, and not a screening test. It cannot detect, rule out or grade any condition, and a reassuring number is not evidence that anything is fine.
- Not a medical device. It makes no claim to diagnose, prevent, monitor, treat or alleviate disease.
- Not personal medical advice. The protocols we link to are general education. Decisions about your health belong with a licensed clinician who knows your history.
Known limitations
- Every input is self-reported and unverified.
- The weights are not calibrated against any population, and the estimate has not been compared against health outcomes.
- Factors that matter and are absent: genetics, medical history, current medication, prescribed treatment, environment, income, access to care.
- The same weights are applied to everyone. Age, sex and existing conditions change what any of these factors is worth in reality; the estimate does not model that.
- Two people with identical answers get an identical number, which is obviously not true of two real bodies.
Changes to this method
If a question, an option or a weight changes, this page changes in the same release and its version number moves. Your historical Prime Age values are not recalculated backwards.
Questions
Write to info@agegen.ai.