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. Suddenly the math is concrete: you have roughly 15,000 days left. Maybe 400 more times you'll see your parents. That clarity doesn't create anxiety. It creates intention. That's the entire idea behind Longlevity.
Why we built this
Longlevity started from a simple frustration: we went looking for a longevity tool we could trust, and couldn't find one.
The free longevity calculators online were mostly toys, fun quizzes with no cited research, or thinly disguised funnels to sell you supplements. The rigorous versions sat behind $2,000 memberships at private longevity clinics. There was no free tool that translates the actual mortality literature into a personal estimate and an action plan you can act on today.
So we went through the key papers behind each habit, the large meta-analyses and cohort studies that pool hundreds of thousands of people, and built a calculator that weights each input to the specific effect sizes those papers found. We used conservative confidence intervals rather than headline figures. We added interaction discounts so compounding improvements don't overclaim, and a cohort adjustment so younger people aren't under-counted by frozen mortality tables. Then we made it free. Every study is named further down this page.
That's Longlevity. The research version of the wellness advice you're already hearing — with citations.
What it is
A free longevity calculator plus an action-plan builder, grounded in CDC data and research covering 40M+ people. You take a 2-minute assessment across the eleven health factors with the strongest mortality evidence. You see your estimated lifespan, your longevity archetype, and the specific habits pulling your trajectory down. You can build a plan, share your results, and compare with people you love to see how much time you have left together.
Your full results (your biological age versus your real age, your archetype, your ranked habit impacts, and personalized recommendations) are free, and so is re-measuring whenever you like and watching your check-ins connect into one trajectory over time. We're giving the whole product away while we're in early access, because we think everyone should be able to see how their habits shape their life. (Longlevity Plus, a membership, comes later as we grow.)
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 weight the slogans don't. That gap (between an abstract "eat better" and a specific "you're losing years here and here") is what the whole product is built around.
The habits that extend lifespan aren't dramatic. The research keeps pointing at the same unsexy things: sleep, movement, food that isn't ultra-processed, people you trust, a reason to get out of bed. What Longlevity does is quantify 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 you, more trips home, more dinners with your kids, more of the people who make it worth being here. That thread runs through the whole product, which is 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.
Last: this research should be free. Every estimate traces back to published studies covering 40M+ people, and the methodology is fully public. A $2,000 longevity clinic shouldn't be the floor for knowing your own trajectory.
The science behind it
Every adjustment in the calculator maps to a specific study: Yin on sleep, Moore on exercise, Jha on smoking, Fadnes on diet, Holt-Lunstad on relationships, the GBD alcohol analysis, Russ on psychological distress, Alimujiang on purpose, Bhaskaran on body weight, and Li's combined-lifestyle study as the calibration anchor, with the whole thing built on national life tables (CDC) for the baseline.
Effect sizes are applied conservatively. We use the most current and methodologically strongest evidence available for each habit (randomized trials where they exist, the largest recent meta-analyses otherwise) and update citations as the field evolves.
For the full study list, specific effect sizes, interaction-discount approach, and what Longlevity can't tell you, see the methodology page.
Who runs this
Longlevity is built and operated by Citron Labs LLC. Editorial content is grounded in primary research: every claim traces to a specific study, never to secondary sources or other blogs. The full editorial standards (no sponsored content, primary sources only, annual content review) are documented on the methodology page.
We are not medical professionals, and Longlevity is not a medical device, diagnostic tool, or substitute for professional medical advice. It's an educational tool. Use it to inform conversations with a healthcare provider, not to replace them.
Contact
Questions, feedback, a study you think should be cited, a correction to anything on the site? Email contact@longlevity.ai.
If your question might already be answered, the FAQ has most of the common ones. For press or partnerships, same address.