Tools

Age Calculator

Enter your date of birth to get your exact age in years, months and days. Also see your age in total days, weeks and months, plus a countdown to your next birthday. Free, no sign-up.

By The Countdown Days · Updated October 10, 2026

Your exact age

–years –months –days

Date of birth

Your date of birth never leaves your device. The entire calculation runs in your browser.

How is exact age calculated?

Count completed years first, then completed months, then the leftover days. The order matters because months hold anywhere from 28 to 31 days, so subtracting the day, month and year columns straight down gives the wrong answer. For example, from 12 August 1995 to 10 October 2026 is 31 completed years (up to 12 August 2026), then 1 full month (up to 12 September 2026), then 28 leftover days. The calculator above does this borrowing automatically, including leap years.

How many days old am I?

Multiply your completed years by 365, add one day for every February 29 you have lived through, then add the days since your last birthday. Someone born on 1 January 2000, for instance, had lived 9,779 days by 10 October 2026. Doing it by hand is error-prone because of the leap days, which is why the calculator shows your total days, weeks and months alongside the familiar years-months-days figure.

What if you were born on February 29?

Leap day babies legally age one year on February 28 or March 1 in non-leap years, depending on the jurisdiction. Most places treat February 28 as the birthday in common years, while a few use March 1. For the "days until next birthday" count, this calculator uses February 28 in non-leap years and the true February 29 when it exists. Either way, you still get a birthday every year; only the once-every-four-years date is special.

How do you calculate age for official forms?

Use your completed years as of the date the form asks about. If a form asks for your age "as of" a certain date, count full years from your birth date to that date, subtracting one if your birthday had not occurred yet that year. For anything precise, like insurance or school admission cutoffs, enter the exact birth date rather than just the year. A one-day difference can matter when eligibility changes on a birthday.

Why do people track their age in days?

Mostly for fun, but with a practical edge. Milestone counts like 10,000 days old (about 27 years and 4 months) make memorable celebrations, and parents love tracking a baby's age in weeks and days. Athletes and actuaries use day counts for precise eligibility windows. And there is something grounding about seeing a big number: it turns an abstract age into a concrete tally of days lived. If a milestone is coming up, start a birthday countdown to celebrate it properly.

Frequently asked questions

Is this age calculator accurate?

Yes. It counts completed years, months and days with proper borrowing across month boundaries and fully accounts for leap years, including century rules.

Is my date of birth stored or sent anywhere?

No. The calculation runs entirely in your browser on your device. Nothing is uploaded, stored or shared.

Can I calculate someone else's age?

Yes. Enter any past date of birth and the calculator returns that person's current age. Useful for parents filling in forms for children.

Why does another calculator give a slightly different day count?

Different calculators use different conventions: some count both the start and end dates, others count only the days strictly between them. This calculator counts the number of full 24-hour days elapsed since birth, which is the standard approach.

Does the calculator work for future dates of birth?

No. A birth date in the future is not valid, and the calculator will ask you to enter a date in the past. For a baby on the way, try our due date countdown instead.

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