Guides
Biological age and speed of aging — measured honestly, for free.
Biological Age Test: How Old Is Your Body, Really?Your biological age can differ from your birthday age by years. Take a free biological age test based on your habits — see how your body really compares, and what moves the needle.How Fast Are You Aging? Your Speed of Aging, FreeBryan Johnson spends millions tracking his speed of aging. You can estimate yours for free — from your habits, in two minutes. Here's how pace-of-aging works and how to slow your clock.Free Biological Age Calculator (No Blood Test Needed)A free biological age calculator that works from your lifestyle — no signup, no blood draw, no data collected. Optional precise mode uses nine checkup values (PhenoAge).How to Lower Your Biological Age (What Actually Works)The habits that move your biological age, ranked by evidence — and the hype that doesn't. A no-nonsense guide, plus a free way to see your starting point.Biological Age vs Chronological Age: What's the Difference?Chronological age is your birthdays. Biological age is how old your body behaves — and they can differ by years. Here's what each means and how to find yours, free.Free Longevity Test: How Long Will You Live?A free, instant longevity estimate from your habits — no signup, no blood draw, nothing collected. See your estimated lifespan as a range (not a fake exact date) and what moves it.PhenoAge Calculator: Your Blood-Based Biological Age (Free)PhenoAge turns nine standard blood values into a validated biological age (AUC ~0.88). Use the free PhenoAge calculator — no signup, computed on your device, nothing stored.Life Expectancy Calculator: A Range, Not a Date (Free)A free life expectancy calculator that's honest about uncertainty. Instead of one scary number, it shows a median and an 80% range from your habits — and what changes it. No signup.How Many Years Does Smoking Take Off Your Life?On average, smoking costs about a decade of life — but quitting wins much of it back, and quitting before 40 avoids most of the risk. See your own number and simulate quitting, free.How Much Does Exercise Add to Your Life?Meeting basic activity guidelines is linked to roughly 3–4.5 more years of life — and the biggest jump is from zero to a little. See what exercise adds to your estimate, free.How Much Does Alcohol Shorten Your Life?It's dose-dependent: light drinking's effect is small and debated, while heavy drinking costs years. See where your level sits and what cutting back returns — a free estimate, no signup.How Does Sleep Affect Your Lifespan?Both too little and too much sleep are linked to higher mortality — the sweet spot is around seven hours. Here's what the research says, and how to see it on your own clock. Free.Does Cardio Fitness Affect How Long You Live?Cardiorespiratory fitness is one of the strongest predictors of lifespan — and in big studies there's no point where more stops helping. Here's what it means, and how to see it on your own clock.How Does Being Overweight Affect Your Life Expectancy?It's dose-dependent and U-shaped: a moderate range is linked to the lowest risk, while higher BMI is associated with years lost. See where you sit and what changes it — a free estimate, no signup.Grip Strength and Longevity: What Your Handshake Says About Your LifespanA weak handshake predicts mortality risk better than you'd expect — sometimes better than blood pressure. Here's what the largest studies on grip strength and longevity actually found, and what to do about it.Does Loneliness Shorten Your Life? The Science of Social Connection and LongevityWeak social ties are linked to a mortality risk on par with smoking. Here's what the largest studies on loneliness, isolation, and lifespan actually found — and what narrows the gap.Ultra-Processed Food and Life Expectancy: What the Research Really ShowsTwo large cohorts link ultra-processed food to higher mortality, and a rare controlled trial found a mechanism: people eat ~500 more calories a day on it without noticing. Here's the actual evidence.