This free metabolic age calculator asks six quick questions about your body and habits. You see your estimated metabolic age straight away, and you can also get a personal 3-step plan by email.
How the calculator works
We start from your real age and add or subtract years for five markers, using thresholds from public guidelines:
- Waist-to-height ratio. Keeping your waist under half your height is a widely used marker of lower metabolic risk (Ashwell and colleagues).
- Weekly activity. The World Health Organization recommends at least 150 minutes of moderate activity a week (WHO, 2020).
- Strength training. The same WHO guidelines recommend muscle-strengthening activity on 2 or more days a week.
- Sleep. Adults need 7 or more hours a night (American Academy of Sleep Medicine and Sleep Research Society).
- Resting heart rate. A lower resting heart rate generally reflects better aerobic fitness.
The result is an estimate for education and motivation. It is not a medical test and cannot diagnose any condition.
What your metabolic age result means
| Your result | What it suggests |
|---|---|
| 5 or more years below your real age | Your habits are working hard for you. Keep them. |
| Within 4 years of your real age | About average for your age, with room to gain years back. |
| 5 to 9 years above your real age | One or two habits are pulling you older. Your email plan shows which. |
| 10 or more years above your real age | Worth acting on now, and worth a check-up with your doctor. |
The biggest swings usually come from waist size and strength training, because both are closely tied to how well your body handles blood sugar.
How to lower your metabolic age
- Shrink your waist first. Check where you stand with our waist-to-height ratio calculator.
- Lift twice a week. Muscle is your largest store for blood sugar. Our strength guides show how to start after 40.
- Eat enough protein. It protects muscle as you age. Find your number with the protein calculator.
- Walk more, especially after meals. 150 minutes a week is the target, and a 10-minute walk after eating blunts blood sugar spikes.
- Protect your sleep. Seven hours or more helps appetite and insulin sensitivity. Read our better sleep tips.
Want the science behind it? Read what metabolic age says about longevity and our guide to metabolic health after 40.
Metabolic age calculator FAQ
What is metabolic age?
Metabolic age compares how your body is doing on key health markers with what is typical for your age. A metabolic age below your real age suggests your habits are protecting you; a higher one points to where you can improve.
Is this the same as a body-composition scale reading?
No. Smart scales estimate metabolic age from body fat and basal metabolic rate. This calculator uses lifestyle and body-shape markers instead, so the two numbers will differ.
Can you lower your metabolic age?
Yes. Because it is built on habits and body shape, it responds to change. A smaller waist, two strength sessions a week, more daily movement and better sleep can lower it within a few months.
How often should I re-test?
Every 8 weeks is a good rhythm. That is long enough for real changes in your waist, fitness and resting heart rate to show up. If you tick the box, we email you a reminder.
What do you do with my email?
We send the report you asked for. If you tick the box, we also send three short follow-up tips and a reminder to re-test in 8 weeks. Every email has an unsubscribe link. See our privacy policy.
Sources
- WHO guidelines on physical activity and sedentary behaviour (World Health Organization, 2020)
- Ashwell M. et al. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors (Obesity Reviews, 2012)
- Watson N.F. et al. Recommended amount of sleep for a healthy adult (Sleep, 2015)
