Age Calculator
Calculate your age in years from your birth date. Optionally enter an "as of" date to find your age at a specific point in time. Uses 365.25 days per year to account for leap years.
Age calculator
Age
What is this?
An age calculator computes how many years (and optionally months, days) have passed between your birth date and a reference date. It accounts for leap years by using 365.25 days per year on average, which gives more accurate results than assuming exactly 365 days. You can enter an "as of" date to find your age at any point in the past or future. This is useful for legal forms, historical research, or planning milestones. The calculation handles all calendar quirks including leap years correctly.
When to use
Use to find your exact age, calculate someone's age at a past or future date, or verify age for forms. Example: How old was I on Jan 1, 2020? Or: How old will I be in 2030? Legal documents often require age as of a specific date. Parents track children's ages for school or medical forms. Historians calculate ages of historical figures. Anyone planning a milestone (retirement, eligibility) can use it to project future age.
How to use
Enter your birth date. Optionally enter an "as of" date to calculate age at a specific point in time.
Uses 365.25 days per year to account for leap years.
Frequently asked questions
- Age is calculated as the difference between the birth date and the reference date, using 365.25 days per year to account for leap years.
- A calendar year averages 365.25 days due to leap years (every 4 years we add a day). This gives more accurate age calculations.