Age Calculator
Enter a date of birth to get an exact age in years, months, and days — plus total weeks, days, hours, and a countdown to the next birthday. Free, instant, and private.
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About this age calculator
This tool works the way a calendar works, not the way a rough formula does. Instead of dividing the number of days you have been alive by 365.25 and hoping the rounding lands well, it walks the actual calendar from your date of birth to the target date: it counts full years first, then full months, then the remaining days, respecting the real length of every month it passes through — including every February 29 along the way. That is why the answer it gives you will match what an official form, a school admission office, or a government eligibility rule expects, where "age" almost always means completed calendar years.
The exact year–month–day breakdown is only half of what people usually need, so the tool also converts your age into totals: months, weeks, days, and hours lived. These totals are computed independently from the raw span between the two dates, which is why total days will never equal your years multiplied by 365 — leap days are real days, and this calculator counts them. As a bonus, it tells you which day of the week you were born on and how many days remain until your next birthday, including which weekday that birthday falls on.
A detail most quick calculators skip: the "age at this date" field. Age is not only asked about today. Visa applications want your age on the date of travel. School admissions in many countries hinge on your child's age on a specific cut-off date, often June 1 or September 1. Pension and retirement paperwork asks what your age was on the last day of a financial year. Set the second date to any of those and the calculation adjusts instantly — past or future.
If your birthday is February 29, the calculator observes it on February 28 in non-leap years — the convention most age calculators and several legal systems use for when a leap-day birthday is "completed." A few jurisdictions use March 1 instead, so if you need a legally binding answer for a leap-day birthday, check the rule that applies where you live. Your total days, weeks, and hours are counted precisely against the real calendar either way.
Your date of birth is saved only in your own browser's local storage so the tool remembers it on your next visit. Nothing is transmitted, and clearing your browser data removes it completely.
Frequently asked questions
How is exact age calculated in years, months, and days?
The calculator counts completed calendar years from your date of birth, then completed calendar months, then leftover days using the true length of the month involved. So someone born on January 31 checking on March 1 gets "1 month, 1 day" in a non-leap year and "1 month, 2 days" would never appear, because February's real length is respected.
Why don't my total days equal my age in years times 365?
Because leap years add a day roughly every four years. The total-days figure is the true count of days between the two dates, so a 40-year-old will typically see about 10 more days than 40 × 365.
Can I calculate my age on a past or future date?
Yes. Change the "Age at this date" field to any date — a school cut-off, a travel date, a retirement date — and the result updates for that day instead of today.
What happens if I was born on February 29?
In years without a February 29, the calculator counts February 28 as the day your birthday completes — the convention most calculators follow. Some countries' laws use March 1 instead, so check your local rule if it matters legally. In leap years, your birthday is counted on February 29 as normal.
Is my date of birth stored or sent anywhere?
It is saved only in your own browser (local storage) so the tool can pre-fill it next time. It is never uploaded — the entire calculation runs in JavaScript on your device.