GrimAge Explained + Lifestyle Habit Score
GrimAge is a DNA methylation "clock" published by Lu, Horvath and colleagues in 2019. It is calculated from a blood sample measured on a methylation array, plus age and sex. This page cannot calculate GrimAge. Instead it explains what GrimAge is and gives an educational points score for habits, such as smoking, that research links with it.
Before you start
Method : Lifestyle habit score — a custom points score written by this site. Each answer adds or subtracts the points shown in the Methodology table below.
Validation : Unvalidated. The points have never been tested against any laboratory measurement or health outcome, and the result is not an age.
Review : not reviewed by a qualified clinician. Educational only — not a diagnosis or a medical test.
This is not GrimAge. GrimAge can only be measured from a blood sample. No lifespan prediction is given.
Your answers stay in this browser tab; nothing is sent or stored.
Packs per day × years smoked. Choose 0 if you never smoked.
Answer the questions, then press Calculate score.
How to Use This Calculator
- Answer each question honestly.
- Press Calculate score.
- Read the breakdown to see which answers add points.
Methodology & assumptions
Your score is the sum of the points below. The weights are this site's own judgement, chosen only to rank habits roughly by how often research links them with older epigenetic-clock results. They are not coefficients from the GrimAge model, which uses methylation data we do not have. Sex, education and illness were removed from the score because they are not habits.
| Factor | Answer | Points |
|---|---|---|
| Smoking status | Never smoked | 0 |
| Former smoker | +2 | |
| Current smoker | +5 | |
| Lifetime smoking (pack-years) | 0 | 0 |
| Under 10 | +1 | |
| 10–30 | +2 | |
| Over 30 | +3 | |
| Body mass index (BMI, kg/m²) | Under 18.5 | +1 |
| 18.5–24.9 | 0 | |
| 25–29.9 | +1 | |
| 30–34.9 | +2 | |
| 35 or more | +3 | |
| Physical activity | Little or none | +2 |
| 1–2 days a week | +1 | |
| 3–4 days a week | 0 | |
| 5+ days a week | -1 | |
| Usual diet | Mostly processed / fast food | +2 |
| Mixed | 0 | |
| Mostly vegetables, fruit, whole grains, legumes | -1 | |
| Alcohol (drinks a week) | None | 0 |
| 1–3 | 0 | |
| 4–7 | +1 | |
| 8 or more | +2 | |
| Sleep per night | Under 6 hours | +1 |
| 6–9 hours | 0 | |
| Over 9 hours | +1 |
Worked examples
Current smoker, 20 pack-years, BMI 27, active 1–2 days, mixed diet, 1–3 drinks, 7 h sleep: 5 + 2 + 1 + 1 + 0 + 0 + 0 = +9 points — several listed risk habits.
Never smoked, BMI 22, active 5+ days, mostly whole foods, no alcohol, 7 h sleep: 0 + 0 + 0 − 1 − 1 + 0 + 0 = −2 points — few listed risk habits.
Understanding your result
The score can only describe your answers. It cannot estimate your GrimAge, your epigenetic age, your risk of disease or how long you will live. Two people with the same score can have very different laboratory results. If you want a real epigenetic clock result, it must come from a laboratory test, and its meaning is best discussed with a doctor.
Sources & further reading
- Lu AT, Quach A, Wilson JG, et al. DNA methylation GrimAge strongly predicts lifespan and healthspan. Aging 2019;11(2):303-327.
- Horvath S. DNA methylation age of human tissues and cell types. Genome Biology 2013;14:R115.
The points table is our own convention and is not taken from these papers.
Frequently Asked Questions
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