Age Calculator
Work out an exact age in years, months, weeks, days, hours, minutes and seconds from any date of birth.
Enter a valid date of birth on or before the “age at” date.
How to use the Age Calculator
- Enter your date of birth.
- Optionally change the "age at" date to calculate age on a past or future day.
- Read your exact age broken down into multiple units.
- See how many days remain until your next birthday.
Examples
| Input | Output | Notes |
|---|---|---|
DOB 1990-06-15, today 2026-08-31 | 36 years, 2 months, 16 days | Also shown in total weeks, days, hours. |
DOB 2000-02-29 | Handles leap-year birthdays correctly |
What the age calculator shows
Enter a birth date and the tool reports your chronological age in calendar form (years, months, days) and as running totals: total months, total weeks, total days, total hours, minutes and seconds lived. It also tells you which weekday you were born on and counts down to your next birthday.
Why the breakdown is useful
- Filling in official forms that ask for age in years and months
- Paediatric and academic cut-off dates
- Milestone celebrations (10,000 days old)
- Calculating the age gap between two people
How months are counted
Month lengths vary, so the calculator anchors to the calendar: from 15 Jan to 15 Mar is exactly 2 months, regardless of whether February had 28 or 29 days. Left-over days are counted from the last monthly anniversary.
Frequently asked questions
How is age calculated?
The calculator subtracts the date of birth from the target date, carrying months and days the way people naturally count age: you are "36 years and 2 months" until the day before your birthday, then you turn 37.
Does it handle leap years?
Yes. February 29 birthdays are supported, and the day, hour and second totals account for every leap day in the interval.
Can I calculate age on a future date?
Yes. Change the "age at" field to any future date to find out how old you (or someone else) will be then.
What is chronological age?
Chronological age is simply the amount of time that has passed since birth, which is exactly what this tool reports. It differs from "biological age" estimates used in health contexts.
Is my date of birth stored?
No. The calculation happens in your browser and nothing is submitted or saved.