Age Calculator
This age calculator turns any date of birth into an exact age in years, months and days. Enter a birth date and an as-of date to calculate age at any point in time, see the total days you've lived, and use it as a birthday calculator with a countdown to your next one. Our guide explains how age is calculated precisely, and the BMI calculator is handy for other quick health checks.
Last updated July 19, 20263 min read
Years
31
Months
2
Days
27
Total days lived
11411
Days until next birthday: 277
How to calculate age from a date of birth
- 1
Pick a date of birth
Use the date picker or type in YYYY-MM-DD.
- 2
Set the as-of date
Defaults to today. Change it to calculate at any past or future date.
- 3
Review the results
Age in years/months/days, total days lived, and countdown to the next birthday.
Benefits
- Handles leap years and month lengths correctly.
- Works for any date — past, present, or planning ahead.
- Shows total days lived, useful for milestones.
- Runs entirely in your browser.
Common uses
- Age verification for forms and applications
- Planning birthday celebrations
- Historical or genealogy research
- Counting milestones like 10,000 days lived
Frequently asked questions
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