Date Diff Calculator — Days Between Dates & Age Find the difference between two dates (and your age).
100% offline
Input21 chars · 2 lines
Output154 chars
1,521 days apart
Years          4
Months         2
Days           0
Total days     1,521
Total hours    36,504
Total minutes  2,190,240
Summary        4 years and 2 months

About Date Diff Calculator — Days Between Dates & Age

Working out how far apart two dates are sounds simple until months have different lengths and leap years get in the way. This free date difference calculator finds the gap between any two dates and breaks it down the way a calendar actually works — exact years, months, and days — plus the raw total in days, hours, and minutes and a plain-English summary.

It's order-independent: enter the dates in either order and you get the same magnitude, so it's just as good for "how long until a deadline" as for "how long ago". An Age mode does the same arithmetic against today's date, so you can calculate exactly how old someone is from their birthday.

Everything runs entirely in your browser. No dates are uploaded, nothing is logged, and it works fully offline.

Features

  • Calendar-correct breakdown: exact years, months, and days
  • Raw totals in days, hours, and minutes
  • Order-independent — dates can go in either order
  • Age mode: measure a birthdate to today
  • 100% offline, nothing leaves your browser

How to use

  1. Keep Difference selected and enter two dates, one per line.
  2. Read the breakdown — years/months/days plus total days, hours, and minutes.
  3. Switch to Age and enter a single birthdate to get exact age as of today.
  4. Copy the result with the copy button.

Frequently asked questions

How are the years, months, and days calculated?

By stepping through calendar fields rather than dividing milliseconds, so each month uses its real length and leap years are handled exactly. The total-days figure is the raw count, which is why it can differ from "years × 365".

Does the order of the two dates matter?

No. The calculator always reports the absolute gap, so entering the later date first gives the same result as the other way around.

How old am I — how do I calculate my age?

Switch to Age mode and enter your birthdate. The calculator runs the same date difference between your birthday and today, returning your exact age in years, months, and days lived — so it doubles as a precise age calculator.

Is my data private?

Yes. All calculation happens locally in your browser. No dates are sent to a server, and the tool keeps working with no network connection.

Everything runs locally in your browser — your input is never uploaded.