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ConduitTools by ConduitCode Labs

Calculators

Age Calculator

Turn a date of birth into an exact age in years, months and days, with the totals in months, weeks and days, and how long it is until the next birthday.

  • Free
  • No sign-up
  • Runs in your browser
Quick guide

How to use this tool

  1. Enter the date of birth in the first box.

  2. Leave the second date as today, or set it to work out the age on a particular day.

  3. Read the exact age in years, months, and days, the totals in weeks and days, and how long it is until the next birthday.

How to use this tool
  1. Enter the date of birth in the first box.

  2. Leave the second date as today, or set it to work out the age on a particular day.

  3. Read the exact age in years, months, and days, the totals in weeks and days, and how long it is until the next birthday.

Loading the tool…

What it covers

An age the calendar agrees with.

Useful for forms, school and sports age groups, eligibility dates and settling arguments about exactly how old someone is.

Exact, not approximate

Years, months and days counted on the calendar, so month lengths and leap years are handled properly rather than averaged.

Any date, not just today

Leave the second date as today, or set it to work out how old someone was, or will be, on a particular day.

Every total at once

Total months, weeks and days, the weekday they were born on, and the countdown to the next birthday.

Frequently asked questions

How are leap-year birthdays handled?

A 29 February birthday has no anniversary in a common year, so this calculator treats 28 February as the birthday in those years. That matches how ages are normally counted and keeps the age and the next-birthday date consistent with each other. A note appears on the result whenever that rule is being used.

Why not just divide the days by 365?

Because years are not all 365 days and months are not all the same length. Dividing gives an answer that drifts by a day or more. This counts whole calendar years, then whole months, then the days left over.

Can daylight saving change the answer?

No. A date here has no time attached, and the arithmetic is done on whole days as integers, so a clock change cannot shift a result by a day. That is a common bug in date tools, and it is avoided by design.

Can I work out an age in the past or the future?

Yes. Change the second date to any day and the age is worked out for that day. The date of birth itself has to be on or before it, so a birth date in the future is refused rather than shown as a negative age.

Why is the age in months not just the years times twelve?

Total months counts every whole month that has passed since the birth date, which includes the months of the current partial year. Someone aged 2 years and 5 months has lived 29 whole months.

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