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Age calculator

Work out your exact age in years, months and days from your birth date.

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Age in days calculatorConvert your age into total days, weeks and approximate years.Retirement age calculatorEstimate when you can retire based on your savings and contributions.Next birthday countdownCount the days until your next birthday and the age you'll turn.Date difference calculatorCount the days, weeks and months between two dates.Add business days calculatorFind the date a number of working days after a start date (weekends skipped).Add or subtract days from a dateFind the date a number of days before or after a starting date.Business days calculatorCount the working days (Monday–Friday) between two dates.Generation calculatorFind out which generation you belong to based on your birth year.

The Age calculator turns Date of birth into Years, Months, Days, instantly and for free.

How to use it

  1. Enter your values: Date of birth.
  2. Read the result instantly: Years, Months, Days.

Frequently asked questions

How does the Age calculator work?

It takes Date of birth and derives Years, Months and Days from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

A single value: Date of birth. Nothing else is required — no account, no file upload.

When would I actually use this?

Answering a scheduling question exactly: how many working days until a deadline, what date falls sixty days out, and what time that is for a colleague elsewhere.

What is the most common mistake?

Counting days by subtracting dates and forgetting whether the endpoints are included. Inclusive and exclusive counts differ by one, which is the difference between meeting a deadline and missing it.

What is the difference between the Age calculator and the Age in days calculator?

This one returns Years and Months; the Age in days calculator returns Total days and Total weeks. That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Retirement age calculator is the closest one after this: Estimate when you can retire based on your savings and contributions.

What else is worth having open alongside it?

Next birthday countdown and Date difference calculator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from, and how current are they?

Calendar arithmetic follows the proleptic Gregorian calendar and the IANA time-zone database, so daylight-saving transitions and leap years are handled. Public holidays vary by country and region and are not assumed.

Further reading

All guides →
How-toHow to Calculate Your AgeSubtract your birth year from this year, then take one off if your birthday hasn't come yet. Here's the rule, the common mistake, and how to get an exact age.ExplainerWhat Generation Am I? Birth-Year Cutoffs ExplainedBoomer, Gen X, Millennial, Gen Z or Alpha? Learn the commonly used birth-year ranges, why the boundaries are fuzzy, and how to place yourself if you were born near a cutoff.How-toWhat Day of the Week Was I Born? Find Out in SecondsFind the weekday of any birth date. Learn the quick calculator method and a short introduction to the Doomsday rule for working it out in your head.How-toHow Many Days Between Two DatesSubtract the earlier date from the later, minding month lengths and leap years. Here's how to count it, and whether to include both endpoints.How-toHow to Count Business DaysBusiness days are weekdays minus holidays. Here's what counts, how to work them out between two dates, why holidays complicate it, and where it matters.ExplainerWhat Week Number Is It?Week numbers run from 1 to 52 or 53. Here's how the ISO 8601 system numbers them, why some years have 53 weeks, and where businesses use them.