Know your starting point

Free longevity
calculators.

Small numbers. Longer horizons.

Your fitness, strength and daily habits tell a story. Find your starting point with six free tools — then make your next move count.

No signupRuns in your browserResearch explained

Find your next useful number

One habit starts here.

Free to use. No account needed.

1 minute, or a walk/run test · Free

VO2 max calculator

Estimate aerobic fitness, compare your age group, and see your VO2 max age.

Try the calculator
1 minute · Free

Zone 2 heart rate calculator

Compare three heart-rate methods and find a sustainable training range.

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3 minutes · Free

Biological age test

See how your habits add up to an estimated biological age.

Take the test
1 minute · Free

Protein calculator

Plan a daily protein range, split it across meals, and compare the app target.

Try the calculator
3 minutes · Free

Grip strength test

Compare a grip-meter reading with age and sex norms. Optional personal hang-time log.

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30 seconds · Free

How many steps a day do you need?

Find an age-based steps range and a manageable next step from your current average.

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A little friendly accountability

Make a plan. Compare what you actually record.

Use the protein, steps and Zone 2 ranges to plan a routine. Save or share the full range; a changed target is not a measure of progress.

For a team challenge, record VO₂ max, grip strength or your weekly step average. Save your own baseline, repeat the same method under similar conditions, and compare your records. An optional six-week reminder helps you check back in.

The biological-age quiz is a self-reported estimate. Changes in its result do not measure how fast you are aging.

Explore daily health tracking in Sarvita

From a snapshot to a habit

Make these numbers a daily habit

Connect Apple Health for fitness and activity trends, log your meals, and build a plan with Sar, your AI longevity coach.

Explore Sarvita for iPhone ↗

Understand the numbers

The science behind a longer, stronger life

The four pillars of longevity training ↗Why VO2 max matters ↗Test your fitness age at home ↗

A little more context

Your questions, answered

Which number predicts longevity best?
Cardiorespiratory fitness, often measured as VO2 max, is one of the strongest predictors at a population level. No single number tells the whole story: strength, movement and metabolic health matter too. Read our ranking of longevity biomarkers.
Are these medical tests?
No. These tools turn published population research into educational estimates, not medical tests or diagnoses. A result cannot predict your lifespan or rule out a health condition.
How often should I re-test?
For recorded measurements, use the same method, device and similar conditions when you return. An optional six-week reminder gives you a check-in date; small changes may be measurement noise. Protein, Zone 2 and age-based steps ranges are plans, so changing their targets is not a progress measurement.

Educational estimates only, not medical advice. Population averages describe groups; they do not diagnose you or predict your lifespan.