About Longlevity

Most of us have no real sense of how much time we have left. So we put off the walk. Grab whatever's easy for dinner. Let months slide by without calling the people who matter most. Not because we don't care, because none of it feels urgent.

Then you see a number. Your number. Not a vague "live healthier" nudge, but an estimate grounded in CDC life tables and decades of mortality research. If you're 40, that's roughly 15,000 days. Maybe 400 more visits with your parents. That kind of clarity doesn't create anxiety. It creates intention. That's the entire idea behind Longlevity.

Why we built this

We went looking for a longevity tool we could trust, and couldn't find one.

The free calculators were mostly quizzes with no research behind them, or funnels for supplements. The rigorous versions sat behind $2,000 memberships at private longevity clinics. Nothing in between translated the actual mortality literature into a personal estimate you could act on today.

So we read the key studies behind each habit, built a calculator that weights every answer by the effect sizes those studies found, kept every number deliberately conservative, and made it free. The whole method is public, down to the version number of the model that produced your result.

What you get

You answer 11 questions: the nine habits with the strongest mortality evidence, plus body weight and family history. It takes about two minutes. You see your estimated lifespan, your biological age, and your #1 lever: the single change worth the most years to you. You can share your numbers, compare with the people you love, and read the research behind the habits in the free library.

All of that is free, always, along with a free account and unlimited re-measuring. Save your numbers and once a year, around your birthday, we'll invite you back to re-measure and see how the year treated you. Think of it as an annual longevity physical.

There is one paid product: the Longlevity Report, a one-time purchase that turns your numbers into a plan. Your archetype, every lever ranked by the years it's worth to you, your per-habit breakdown, your ten-year projection, and your next moves in order. The knowing stays free, because everyone should be able to see how their habits shape their life.

What we believe

Generic health advice rarely moves anyone. A concrete number does. When you see that your trajectory is 79, and you could be at 85 if you fixed two specific things, the math has a weight the slogans don't.

The habits that extend life aren't dramatic. The research keeps pointing at the same unglamorous things: sleep, movement, food that isn't ultra-processed, people you trust, a reason to get out of bed. Longlevity's job is to show which of those matter most for you, based on where you are today.

And the point of living longer isn't the number. It's the shared time it buys: more trips home, more dinners with your kids, more of the people who make it worth being here. That's why the calculator has a Compare feature, so you can see how many years you have left with the people you love and let that shape what you do with them.

What we will never do

• Sell your data, or show you ads. Your answers produce your results and nothing else.
• Push supplements, protocols, or products. We have nothing to sell you except the report.
• Charge you automatically. The report is paid once. Nothing renews, and there is a 30-day refund, no questions asked.
• Inflate a number to motivate you. Every effect size is applied at the conservative end of the evidence. We would rather you be pleasantly surprised than misled.
• Pretend to be your doctor. Longlevity is an educational tool. It doesn't diagnose or treat anything.

The science

Every adjustment in the calculator maps to a specific published study: randomized trials where they exist, the largest recent meta-analyses otherwise, with Li's combined-lifestyle study as the calibration anchor and CDC national life tables as the baseline. Habits overlap in their biology, so we discount for interactions rather than adding gains up, and younger users get a cohort adjustment so frozen mortality tables don't undercount them.

We re-read the research every month. When the evidence moves, the model moves with it, and every change is versioned so you can see what shifted and why. The full study list, the effect sizes, and an honest account of what Longlevity can't tell you are on the methodology page.

Who runs this

Longlevity is built and operated by Citron Labs LLC. We are not medical professionals, and Longlevity is not a medical device or a substitute for professional medical advice. Use it to inform conversations with your healthcare provider, not to replace them.

Every claim on this site traces to a primary study, never to another blog. There is no sponsored content. Our editorial standards are public.

Contact

A question, a correction, a study you think we should cite? Email contact@longlevity.ai. We read everything. The FAQ covers most common questions; press and partnerships reach us at the same address.

Go deeper: how the estimate is calculated, the seven longevity archetypes, or the blog.