Age Calculator
Enter your date of birth to find your exact age in years, months and days, total days and weeks, and how long until your next birthday.
What Is Age Calculation and Why Is It Needed?
Age calculation precisely measures the time elapsed between a birth date and a given reference date in years, months and days. In everyday conversation stating your age is easy, but for retirement applications, passport renewals or sports licences the exact month and day count matters.
The tool also shows how many days and weeks old you are and how many days remain until your next birthday. This information is sometimes useful for insurance calculations or verifying official document validity periods.
How to Use
Inputs
The only required input is your birth date (YYYY-MM-DD). The reference date defaults to today; you can change this field to calculate against a past or future date.
Formula and Logic
The millisecond difference between the reference date and birth date is divided by 86,400,000 to get total days. For the year-month-day breakdown, years, months and days are compared in turn; whenever a value goes negative it borrows from the previous unit. This method handles leap years (29 February) automatically and correctly.
Example Scenario
The age of a person born on 15 March 1990 as of 22 April 2026:
| Parameter | Value |
|---|---|
| Birth date | 15 March 1990 |
| Reference date | 22 April 2026 |
| Exact age | 36 years, 1 month, 7 days |
| Total days | 13,187 days |
| Total weeks | 1,883 weeks |
| Next birthday | 15 March 2027 (327 days) |
Frequently Asked Questions
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