Free Longevity Test: How Long Will You Live?
Updated 6/2/2026 · 3 min read
"How long will I live?" is unanswerable as a single number — even identical twins differ by ~14 years. But you can get an honest estimate as a range, and see what shifts it.
This longevity test is free, runs on your device, and shows a band rather than a fake exact date — because anyone promising a precise date is selling certainty that doesn't exist.
Why a range, not a date
Mortality is genuinely uncertain at the individual level. The best models explain only a fraction of the variance, so a single 'you will die at 81' number is statistically dishonest. We show a median plus an 80% range so the uncertainty is visible, not hidden.
What the test uses
Your lifestyle (smoking, exercise, diet, sleep, alcohol, conditions) mapped onto cohort hazard ratios and a life table — the same machinery actuaries use, made personal and free. Optionally, nine standard blood values for a validated estimate.
Nothing is sent to a server. It's a mirror, not an oracle.
The useful part
The number isn't the point — the levers are. The test shows which habit is costing you the most time, and the simulator shows what changing it does. That's where a longevity test earns its keep.
FAQ
Is the longevity test free?
Yes — free, no signup, no payment, nothing collected. It runs on your device.
How accurate is it?
It's a statistical estimate shown as a range, not a precise prediction. No tool can know your exact lifespan. Treat it as a mirror and a motivator, not a verdict. In crisis, call or text 988 (US).
Can I change my result?
The estimate reflects current habits. The built-in simulator shows how quitting smoking, exercising, or sleeping better shifts the range.
DaysLeft is a statistical mirror, not a medical diagnosis. For health concerns, talk to a doctor. In crisis (US): call or text 988.