Age Calculator
Enter a date of birth to instantly calculate the exact age in years, months, and days as of today.
How to use the Age Calculator
Type or paste a date of birth in YYYY-MM-DD format (for example, 1998-04-23) into the box above, then click "Calculate age." The tool instantly works out the exact age as of today, broken down into years, months, and days — not just a rounded number.
Why calculate your exact age?
A simple "how old are you" question usually gets a rounded answer, but there are plenty of situations where the precise figure matters: filling out official forms, checking eligibility for age-restricted services, working out a child's exact age for a medical or school record, or just settling a birthday argument with a sibling. This calculator handles the date math for you, including leap years, so you don't have to count on your fingers.
Frequently asked questions
Does it account for leap years?
Yes. The calculator uses JavaScript's native date handling, which correctly accounts for leap years and varying month lengths when working out the years, months, and days between two dates.
What date format should I use?
Enter the date of birth as YYYY-MM-DD (year-month-day), for example 2000-01-15 for 15th January 2000.
Is my date of birth stored or sent anywhere?
No. This tool is part of the Toolyard collection of free, browser-based utilities. All calculations run locally in your browser — nothing you enter is uploaded to a server or stored anywhere.
Can I calculate age as of a future or past date instead of today?
Currently the tool calculates age as of today's date. For a specific target date, subtract the difference manually, or check back — this is a feature we're considering adding.
Why "just subtract the years" isn't quite right
If someone's birthday hasn't happened yet this year, simply subtracting birth year from the current year overstates their age by one — this is the classic off-by-one mistake people make doing age math in their head. An accurate calculation needs to check whether the birth month and day have already passed in the current year, which is exactly what an automated calculator handles correctly every time.
Beyond "how old am I"
This kind of calculation is also used to determine exact age in months and days (useful for infant health milestones and vaccination schedules), to check eligibility for age-restricted services or age-based pricing tiers, and to calculate age as of a specific past or future date rather than today — for example, "how old will I be on my retirement date" or "how old was I when this photo was taken."
Frequently asked questions
Does this account for leap years?
Yes — the calculation is based on actual calendar dates, so leap years are automatically factored into the day count.
Can I calculate age as of a future date?
Yes, enter any future date instead of today's date to see the projected age at that point.