Age Calculator
Enter your date of birth to calculate your exact age in years, months, and days — plus totals and your next birthday.
Result
- Total months
- Total weeks
- Total days
- Total hours
- Born on
- Next birthday
- Days until next birthday
Examples
| Date of birth | Target date | Result |
|---|---|---|
| 2000-02-29 | 2026-09-29 | 26 years, 7 months, 0 days |
| 1990-10-15 | 2026-01-01 | 35 years, 2 months, 17 days |
Formula & Methodology
Age is computed using calendar arithmetic rather than dividing total days by 365:
years, months = calendar difference; days = remainder after adding whole monthsThis correctly accounts for leap years and the varying number of days in each month.
How to Use
- Enter your date of birth.
- Optionally set a different "Calculate age on" date — otherwise today's date is used.
- View your exact age breakdown and next birthday countdown.
Frequently Asked Questions
How is age calculated for someone born on February 29?
In non-leap years, a February 29 birthday is observed on February 28 for the purposes of computing the next birthday. Your exact elapsed years/months/days are still calculated precisely using calendar arithmetic.
Why not just divide the number of days by 365?
That approach drifts over time because of leap years and months of different lengths. This calculator uses real calendar arithmetic (adding whole months and days) so the years/months/days breakdown is always exact.
What if I enter a future date of birth?
The tool will show an error, since a birth date cannot be after the target date.
Can I calculate someone’s age on a specific past or future date?
Yes — set the "Calculate age on" field to any date instead of leaving it as today.
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