Age Calculator
Calculate your exact age in years, months, and days from your date of birth.
- Free forever
- Instant results
- Private — runs in your browser
How to use the Age calculator
Pick your date of birth. Your exact age in years, months and days appears instantly, along with the total days, weeks and hours you have lived and a countdown to your next birthday.
Below that you get a “journey of life” dashboard: your generation, star sign, life stage, fun estimates such as heartbeats and steps, and the dates of milestones like your 10,000th day.
The link in your address bar updates as you go, so you can bookmark it or send it to a friend and they will see the same result.
Formula
Age = whole calendar months from your birth date to today (split into years and months), plus the remaining days since your last “month-iversary”.
If your birthday falls on a day the current month doesn’t have (e.g. the 31st, or 29 February), the last day of that month is used.
Frequently asked questions
How is exact age calculated?
We count the whole calendar months between your birth date and today, split them into years and months, then count the remaining days. Leap years and months of different lengths are handled by working with real calendar dates rather than averages like 365.25 days.
What if I was born on 29 February?
In non-leap years this calculator treats 28 February as your birthday, so you turn a year older on the 28th. Some countries legally use 1 March instead, so official documents may differ by one day.
Why does my age in days look different on another calculator?
Some calculators count both the start and end date, or use averaged month lengths. We count the number of midnights between your birth date and today, which is the standard way to express age in days.
Are the heartbeat and breath counts accurate?
They are illustrative estimates using population averages (80 heartbeats and 16 breaths per minute, 8 hours of sleep a night). Your real numbers depend on your age, fitness and health.
Is the 80-year lifespan accurate?
80 years is a round benchmark used for the visualisation. Actual life expectancy varies widely by country, sex, health and lifestyle.
Is my date of birth stored anywhere?
No. Everything is calculated in your browser. Your date of birth only appears in the page address so the result can be bookmarked or shared — it is not sent to or stored on our servers.