Age Calculator
Enter a birthdate for exact age plus rough life stats. Estimates use common averages, not medical data.
Exact age
0 years, 0 months, 0 days
Total days alive0
Approx heartbeats0
Approx breaths0
Full moons0
About this tool
Age Calculator
Age Calculator gives your exact age in years, months and days from any birth date.
How to use it
- Enter the birth date.
- Read the exact age broken down by unit.
Why age arithmetic is fiddly
Years and days are well defined, but months are not: they range from 28 to 31 days, so the number of days in a given month span depends on which months you crossed. The convention is to count whole months first and take the leftover days.
Leap years add the other wrinkle. Anyone born on 29 February has a birthday in only one year out of four, and different systems disagree about whether their legal birthday falls on 28 February or 1 March in other years.
When it helps
- Working out an exact age for a form or an application.
- Calculating age at a specific past or future date.
- Finding how many days until a milestone birthday.
- Checking eligibility against an age cutoff.
Common mistakes
- Assuming a year is always 365 days when converting. Leap years mean a person's age in days is not simply years times 365.
- Confusing age in years with years elapsed. Someone is 0 years old for their entire first year.
