Exact Age Calculator — Find Your Age in Years, Months & Days

Private by default

Get an exact age or date answer as soon as the page opens.

The calculator starts with a sample date so you can see a real result immediately, then swap in your own birthday or date range. Nothing is uploaded or stored.

Exact years, months, days, and hours
Leap-year and DST-safe date math
Shareable links that stay on your device

Secure your personal identity information

Your birth date is key personal data. Protect your family's personal logins, banking, and identity profiles with secure credential management. Read our review of the best password managers →

A simple age calculator that respects your time

Determine your exact age in years, months, weeks, and days from your date of birth. The same browser-based calculator also measures the distance between two dates or helps you add and subtract days without opening a spreadsheet. All calculations run client-side, so your birth date stays on your device and is never shared or stored.

How to use it

Pick a tab. Age from DOB takes a date of birth (and optional birth time) and reports your exact age.

Days between dates takes any two dates and counts the calendar days between them.

Add or subtract days takes a start date and a day count (negative to go backwards) and gives you the resulting date.

Hit Copy share link — every input is stored in the URL hash, so you can paste it into a chat without us ever seeing it.

How the math works

Calendar arithmetic. Years, months, and days are counted in calendar terms — borrowing from the next unit down exactly the way you would on paper. A child born June 30 turns 1 on June 30, not 365.25 days later.

Leap-year safe. Feb 29 birthdays fall on Feb 28 in non-leap years, matching most jurisdictions' bureaucratic conventions.

DST safe. The hour remainder is computed from wall-clock time, so a daylight-saving switch between birth and today cannot inject a phantom hour into the result.

Local-only. All math runs against your local time zone. No conversions, no surprises.

Range. Years 1900 through 2100 inclusive. Outside that, the result would push against JS Date overflow and we'd rather you knew than guess.

FAQ

How exact is the age calculation?

We compute calendar age the way humans count it: full years first, then full months, then full days, then remaining hours. A person born on Feb 29 is reported as having a birthday on Feb 28 in non-leap years, matching most legal and bureaucratic conventions.

Does it handle leap years and daylight-saving time?

Yes. The day/month/year math uses calendar arithmetic that respects leap years from 1900 through 2100. Hour math uses UTC under the hood so DST transitions never add or drop an hour in the result.

Can I share my result?

Yes. Every input is stored in the URL fragment (the part after #), so copying the address bar gives someone the same dates without us ever seeing them. Nothing is sent to a server.

What does “add 7 days” actually mean?

Seven 24-hour periods from the start date, in your local time zone. We deliberately avoid the “same wall-clock time on the date 7 days later” interpretation so the answer never silently changes across a DST boundary.

Is entering my date of birth on this site safe?

Yes. Date of birth is a sensitive piece of personal identification information (PII). Our age calculator does not send your date of birth to any server. Everything is calculated in-browser. To protect your identity and personal accounts further, read our guide on the best password managers to secure your logins and monitor for leaks.

Does this work offline?

Yes, after the first visit. The page and its scripts are static and get cached by your browser; the calculator runs entirely client-side with no API calls.