Biological age calculator: what the published figures add up to
Worked example: age 45, five answersworked example
34.4 to 38.8
- Published years, summed
- +6.2 to +10.6 ybefore any clamp
- Questions answered
- 5 of 5
- Model version
- 2026-07-30.1
Groups with these answers had life expectancies that work out below a chronological age of 45 - somewhere between 34.4 and 38.8 on this arithmetic.
Realistic range
34.4 years to 38.8 years
Large, and structural rather than statistical. Each term is a life-expectancy difference its own study published in years, but the terms come from different cohorts with different reference groups and different starting ages, and their effects overlap heavily through shared cardiovascular and metabolic pathways. Adding them therefore overstates the combined difference by an amount no publication quantifies. The result is reported as a range, clamped to plus or minus 12 years, and always shown broken down by term.
Read this before you read the number
The addition is ours, not a published model. Each row below is a life-expectancy difference that a named study measured and reported in years. Adding them together is not something any of those studies did, and nothing validates it: the figures come from different populations, with different comparison groups and different starting ages, and the effects overlap heavily — smoking, diet, activity and body weight all act partly through the same cardiovascular pathways, so summing them counts some of the same benefit more than once. The total is therefore clamped to 12 years in either direction and shown as a range. Read the rows; treat the total as an illustration of their combined size.
This is not a clinical or an epigenetic age. Laboratory biological-age measures use methylation or biomarker panels. This asks five questions. It is for reflection, not diagnosis, and it cannot tell you anything about your own life expectancy — these are differences between groups.
Your answers
Where each number comes from
This table is the actual result. The total above is a summary of it.
| Factor | Your answer | Published years | Source |
|---|---|---|---|
| Smoking | Never smoked | 0 yThe reference group for every other row here. | Jha et al., New England Journal of Medicine 2013 |
| Physical activity | About 150 to 300 minutes a week | +3.2 to +3.6 y7.5-14.9 MET-hours per week, the band that straddles the recommended minimum: a gain of 3.4 years (95% CI 3.2-3.6). | Moore et al., PLoS Medicine 2012 |
| Diet pattern | Somewhere in between | +3 to +7 yThe paper's 'feasibility approach' diet - a midpoint between typical and optimal - is modelled at roughly half the optimal gain. A deliberately wide band, because a self-described 'in between' diet is not a measured intake. | Fadnes et al., PLoS Medicine 2022 |
| Alcohol | None, or up to about 100 g a week | 0 yThe reference group. The paper found the threshold for lowest all-cause mortality risk was about 100 g a week. | Wood et al., The Lancet 2018 |
| Body weight | Around 22.5 to 25 | 0 yMortality was lowest at about 22.5-25 in this analysis. | Prospective Studies Collaboration, The Lancet 2009 |
What is deliberately missing
Four things you might expect to see, and why they are not here:
- Resting heart rate. The large meta-analyses report resting heart rate as a hazard ratio for all-cause mortality, not as a difference in years. Turning a hazard ratio into years requires assumptions this site cannot cite, so the term is absent rather than estimated. Track it in the Numbers Log instead.
- Blood pressure. Same reason: the AHA/ACC categories and the cohort literature behind them are expressed as risk, not as years of life. A blood pressure reading belongs in the Numbers Log and in a conversation with a clinician, not in an arithmetic that would need an invented conversion.
- Sleep. Sleep belongs to theballastprinciple.com under the portfolio's placement rules, and the published sleep-duration findings are hazard ratios rather than years in any case.
- Body-mass index between 25 and 30. The Prospective Studies Collaboration reports lowest mortality at about 22.5-25 and gives median-survival reductions for 30-35 and 40-45, but publishes no years figure for the 25-30 band. That band therefore carries zero years - which means 'no published figure', NOT 'no effect'.
Resting heart rate and blood pressure are worth tracking even though they cannot appear here — the Numbers Log is where they belong.
Official sources
- Lifestyle life-expectancy differences, summed (this site's construction)convention — estimate = chronological age - sum of published life-expectancy differences, clamped to +/- 12 years. Verified against Composite - each term carries its own primary source in biological-age-model.json (Large, and structural rather than statistical. Each term is a life-expectancy difference its own study published in years, but the terms come from different cohorts with different reference groups and different starting ages, and their effects overlap heavily through shared cardiovascular and metabolic pathways. Adding them therefore overstates the combined difference by an amount no publication quantifies. The result is reported as a range, clamped to plus or minus 12 years, and always shown broken down by term.)
This adds up life-expectancy differences that five studies published in years - for smoking, activity, diet, alcohol and body weight - and subtracts them from your age. It reports a range, never one number, and shows every figure with the paper it came from. The addition is ours; none of those studies did it.
- Lifestyle life-expectancy differences, summed (this site's construction)convention — estimate = chronological age - sum of published life-expectancy differences, clamped to +/- 12 years. Verified against Composite - each term carries its own primary source in biological-age-model.json (Large, and structural rather than statistical. Each term is a life-expectancy difference its own study published in years, but the terms come from different cohorts with different reference groups and different starting ages, and their effects overlap heavily through shared cardiovascular and metabolic pathways. Adding them therefore overstates the combined difference by an amount no publication quantifies. The result is reported as a range, clamped to plus or minus 12 years, and always shown broken down by term.)
Everything you type here is computed in your browser. Nothing you enter is stored on a server, sent anywhere, or shared — there is no account and no health data to leak.
Frequently asked questions
What is a biological age calculator actually measuring?
Is this the same as an epigenetic age test?
Why does it give a range instead of a number?
Where do the numbers come from?
Why is resting heart rate or blood pressure not included?
Can I add the years back on by changing an answer?
Get a quarterly nudge to re-check your numbers
Four emails a year: a reminder to re-take your numbers, and what changed in the guidance behind these tools. No spam, unsubscribe any time.
Double opt-in: you will get one confirmation email and nothing else until you click it.
The next number
No body metric means much on its own. Here is what this one feeds into.
Related calculators
Every formula on this page is listed with its source on the methodology page, and changes to any reference value are logged in the data changelog. Canonical URL: https://myhealthmywellness.com/biological-age-calculator