Age Calculator
Free age calculator. From a date of birth, see exact years/months/days, total months, weeks, days, hours, and the countdown to your next birthday.
Enter a date of birth to calculate.
Calculate someone's exact age from their date of birth — in years, months and days, plus total months, weeks, days and hours lived. Useful for filling in forms, checking eligibility (voting, retirement, drinking age), planning birthdays, or just for fun.
Enter an optional Age as of date to compute age at a specific moment — for example, someone's age on a contract date or at a historical event. Leave it as today for their current age.
How to use
- Pick the date of birth.
- Leave Age as of set to today, or change it to any other date — past for historical age, future to project a future age.
- Read the age in years, months and days, plus total months, weeks, days and hours, day-of-week born, and countdown to the next birthday.
Frequently asked questions
- How is age calculated?
- We compute the full years between the two dates, then the remaining full months, then the remaining days — matching how people normally say age ("28 years, 4 months and 11 days"). Total days, weeks and hours are computed directly from the millisecond difference.
- Can I calculate age on a past or future date?
- Yes. Change the "Age as of" field to any date — past for historical age, future to project a future age. The date must be on or after the date of birth.
- Does it handle leap years correctly?
- Yes. All calculations go through JavaScript's Date object, which handles leap years, month lengths and daylight-saving transitions correctly.
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