How to Calculate Your Biological Age: 4 Methods Explained
By WellnessVigor · Updated October 15, 2026 · 9 min read
This article contains affiliate links. If you buy through them, we may earn a small commission at no extra cost to you. Learn more.
Two people born in the same year can age very differently. One runs up stairs at 60, the other is out of breath at 45. Your chronological age is the number of birthdays you have had. Your biological age describes how old your body behaves.
There is no single perfect test, but there are four practical ways to estimate it, from a free online quiz to lab tests. This guide explains each one, what it can tell you, and how to lower your number.
Quick answer
You can estimate biological age with (1) a lifestyle questionnaire, (2) the PhenoAge formula using nine routine blood test results, (3) a DNA methylation (epigenetic clock) test, or (4) fitness measures like grip strength and walking speed. Try our free {{/biological-age-calculator/|Biological Age Calculator}}. Not smoking, exercise, healthy weight, a good diet and moderate alcohol are the habits most strongly linked to a younger biological age.
Chronological age only moves forward. Biological age reflects the condition of your cells, organs and systems, and it can be higher or lower than your real age. Scientists use it to predict who is more likely to develop age-related disease, and to test whether lifestyle changes or treatments slow aging.
Important: every method gives an estimate. Different tests measure different things, so they will not all give the same number.
Method 1: a lifestyle estimate (free)
The simplest approach adds or subtracts years based on habits that large studies link to health and lifespan: smoking, exercise, sleep, diet, alcohol, body weight, stress and social contact.
The evidence behind this is strong. A Harvard study of more than 120,000 adults found that people who followed five healthy habits (never smoking, a healthy weight, regular exercise, a healthy diet and moderate alcohol) lived about 14 years longer (women) and 12 years longer (men) from age 50 than people who followed none.
Our Biological Age Calculator uses this approach and shows which habits are adding or taking off years.
- Pros: free, instant, shows what to change.
- Cons: an educational estimate, not a measurement.
Method 2: PhenoAge from a routine blood test
In 2018, researchers led by Morgan Levine created PhenoAge, which combines nine common blood markers with your age to estimate biological age:
| Marker | What it reflects |
|---|---|
| Albumin | Liver function and nutrition |
| Creatinine | Kidney function |
| Fasting glucose | Blood sugar control |
| C-reactive protein | Inflammation |
| Lymphocyte %, white blood cells | Immune system |
| MCV, RDW | Red blood cell health |
| Alkaline phosphatase | Liver and bone |
All nine are on a standard complete blood count (CBC) and metabolic panel, plus a CRP test. In the original research, a higher PhenoAge than chronological age predicted a higher risk of death and age-related disease.
- Pros: uses tests many people already have; validated in large studies.
- Cons: one infection or a bad night can shift markers like CRP; it is a research tool, not a diagnosis.
Want a done-for-you plan? 35 Days to a Leaner You combines a 35-day low-carb meal plan with simple home workouts, so you know exactly what to eat and how to move each day.
Burn calories at home, rain or shine
A magnetic exercise bike is quiet enough for early mornings and small apartments. One purchase, years of workouts for the whole household.
Method 3: epigenetic clocks (DNA methylation)
Epigenetic clocks look at chemical tags called methyl groups on your DNA, which change in predictable ways as you age. The first widely used clock was published by Steve Horvath in 2013. Newer tests like DunedinPACE estimate how fast you are aging right now, rather than a single age number.
- Pros: the most detailed biological measure available today.
- Cons: costly (often $200–500), results differ between companies, and they are not yet used to guide medical care.
Method 4: fitness and function tests
How well your body performs is one of the best real-world signs of biological age:
- Grip strength: in a study of nearly 140,000 adults in 17 countries, weaker grip strength predicted higher risk of death and heart disease.
- Walking speed and the ability to climb a flight of stairs without stopping.
- Resting heart rate and aerobic fitness (VO2 max).
- Balance: standing on one leg for 10 seconds.
These are free to track at home and improve quickly with training.
How to lower your biological age
- Stop smoking — the single biggest factor.
- Move every day and aim for 150+ minutes of activity a week, plus strength training twice a week.
- Sleep 7–9 hours on a regular schedule. See does lack of sleep make you age faster?
- Eat mostly whole foods: vegetables, fruit, beans, whole grains, nuts and fish.
- Keep a healthy waist size. Check yours with our BMI Calculator.
- Limit alcohol and manage stress.
- Stay connected with friends and family.
Useful tools for tracking
These are common, inexpensive options that some people find helpful. We have not personally tested these products. Links go to Amazon so you can check current prices and reviews.
BEST FOR FITNESS TRACKING
Fitness tracker with heart rate
Tracks resting heart rate, steps and sleep, three of the easiest signs of your biological age to improve.
Pros
- Resting heart rate trends
- Sleep and step tracking
Cons
- Estimates, not medical data
- Needs charging
BEST FOR GRIP STRENGTH
Hand grip dynamometer
Measure grip strength at home and track it over months as you get stronger.
Pros
- Simple, objective number
- Shows progress clearly
Cons
- Readings vary by technique
- Not a medical test
BEST FOR BODY COMPOSITION
Smart body composition scale
Watch your weight and waist-related trends over time. See our smart scale guide.
Pros
- Automatic logging
- Trend charts
Cons
- Body fat is an estimate
- App needed
Keep reading
- Biological Age Calculator
- Does lack of sleep make you age faster?
- BMI Calculator
- How to lose weight after 50 for women
Frequently asked questions
How do I calculate my biological age?
The easiest way is a lifestyle questionnaire like our free calculator. For a blood-based estimate, enter nine routine blood test values into the PhenoAge method. Epigenetic DNA tests are the most detailed but cost more.
Can you reverse your biological age?
You can improve the markers that biological age tests use. Quitting smoking, regular exercise, better sleep, a healthier weight and diet are linked with younger biological age scores in studies.
Are biological age tests accurate?
They are estimates. Different tests measure different things, so results vary. They are most useful for tracking change over time with the same method.
What blood tests show biological age?
PhenoAge uses albumin, creatinine, fasting glucose, C-reactive protein, lymphocyte percentage, MCV, RDW, alkaline phosphatase and white blood cell count.
Sources
- Levine ME, et al. An epigenetic biomarker of aging for lifespan and healthspan. Aging (Albany NY). 2018.
- Li Y, et al. Impact of healthy lifestyle factors on life expectancies in the US population. Circulation. 2018.
- Horvath S. DNA methylation age of human tissues and cell types. Genome Biol. 2013.
- Belsky DW, et al. DunedinPACE, a DNA methylation biomarker of the pace of aging. eLife. 2022.
- Leong DP, et al. Prognostic value of grip strength: findings from the PURE study. Lancet. 2015.
This article is for general information only and is not medical advice. See our Medical Disclaimer.