Age Calculator
Enter your date of birth to calculate your exact age.
Date of birth
Your dates stay in your browser
Current age
Complete a valid date of birth to see the age breakdown.
What is an age calculator?
An age calculator compares a birth date with another calendar date. It is useful for birthday planning, personal milestones and checking ages on forms.
How is age calculated?
We count complete calendar years, then complete months, then remaining days. Month-end anniversaries are clamped to the last available day. Total weeks are complete seven-day periods; hours and minutes represent calendar days multiplied by 24 and 1,440.
Why can calculators differ by one day?
Some calculators include the starting day or convert dates through a local timezone. This tool compares calendar dates at UTC midnight, excluding the birth date, so daylight saving changes do not shift the result.
Worked example: a leap-day birthday
For someone born on 29 February 2000, the age on 1 March 2025 is 25 years, 0 months and 1 day. This calculator uses 28 February as the birthday anniversary in non-leap years, so one day has passed since that anniversary. The next birthday is 28 February 2026, 364 days after the calculation date. Legal or administrative conventions may differ.
Leap year birthdays
For February 29 birthdays, this tool uses February 28 as the anniversary in non-leap years. Legal or administrative conventions may differ.
How to use
- Select your birth month and day, then enter your birth year.
- Your current age appears instantly. Enable another date only when you need an age from the past or future.
- Review the years, months and days breakdown, next birthday and calendar totals.
Frequently asked questions
How old am I today?
Enter your date of birth and keep the default calculation date. Your local calendar date is selected when the page opens.
How do you calculate exact age?
We compare calendar anniversaries and months, then count remaining days. We do not divide days by 365.
How old is someone born on February 29?
Here, their age increases on February 28 during non-leap years and February 29 during leap years.
Can I calculate age on a past or future date?
Yes. Choose any calculation date on or after the date of birth.