100% Free · Private · No sign-up

Age & Date Difference Calculator

100% free — calculate your exact age in years, months and days, or find the difference between any two dates. Total days, weeks and next birthday included.

Three simple steps

How to calculate age or date difference online

Pick your dates and get an accurate result in seconds.

  1. 1

    Choose a mode

    Select Age calculator for your date of birth, or Date difference for any two dates.

  2. 2

    Enter your dates

    Use the date pickers to set your birth date, as-of date, or start and end dates.

  3. 3

    Read your result

    See years, months, days, total days, weeks and extra details like your next birthday.

Everything you need

Two date tools in one calculator

Exact calendar math — fast, accurate and private.

Exact age

Your age in years, months and days — not just a rounded number of years.

Date difference

Find how much time passed between any two dates — past, present or future.

Total days & weeks

See the total number of days and weeks between dates at a glance.

Next birthday

Find your next birthday and how many days until you celebrate.

Any as-of date

Calculate age as of today, a past event, or a future date.

100% private

All calculations run locally in your browser. Your dates are never uploaded.

Calculate your exact age or the days between two dates

Need to know your precise age, how many days until your birthday, or how much time passed between two events? This free age calculator and date difference calculator gives you accurate results in years, months and days — plus total days, weeks and more — without installing an app or creating an account.

How the age calculator works

Enter your date of birth and an as-of date (today by default). The calculator counts full years, then remaining months, then remaining days — the same way you'd figure age on paper, but instantly. It also shows total days lived, your next birthday, and days until that birthday.

How the date difference calculator works

Switch to Date difference, pick a start date and an end date, and see the span between them in years, months and days, along with the total number of days and weeks. Useful for project timelines, rental periods, pregnancy tracking, legal deadlines and everyday questions like "how many days since…?"

Leap years and calendar accuracy

The calculator uses real calendar dates, so it correctly handles months with different lengths and leap years. February 29 birthdays and cross-month calculations are all accounted for.

Because everything runs on your device, there's nothing to install and nothing is uploaded. Your dates stay completely private, and the calculator works even when you're offline. This is one of many free browser tools on Uzetool — explore more tools as we add them.

Questions

Frequently asked questions

How do I calculate my exact age?

Enter your date of birth and an as-of date (today by default). The calculator shows your age in years, months and days, plus total days lived and your next birthday.

How do I find the difference between two dates?

Switch to the Date difference tab, enter a start date and an end date, and read the difference in years, months and days, plus total days and weeks.

Does the calculator account for leap years?

Yes. It uses calendar dates and handles varying month lengths and leap years correctly when computing years, months, days and total day counts.

Can I calculate my age as of a past or future date?

Yes. Change the as-of date to any past or future date to see how old you were or will be on that day.

Is the age calculator free and private?

Yes — it's 100% free with no sign-up or limits, and every calculation runs locally in your browser. Your dates are never uploaded. The tool is supported by unobtrusive ads so it can stay free.