Age Calculator
Calculate exact age in years, months, days, and total elapsed days.
Choose a birth date and an age-on date.
What this calculator does
Choose a birth date and comparison date to calculate calendar age, total days, and the next birthday.
Inputs and what they mean
- Date of birth
- — date value.
- Age on date
- — date value.
How to use it
- Choose the date of birth.
- Choose the date on which to measure age.
- Read calendar age, total days, and the next birthday.
Formula
Calendar age subtracts the birth date from the chosen date, borrowing days and months where needed.
Worked example
Age on a chosen date
Use a past birth date and today or another comparison date.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Common questions
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Calculate elapsed hours and minutes between two times, including overnight.
Everyday