Age calculator
Pick a date of birth and see how old someone is: in whole years, exactly in years, months and days, and in weeks and days. Leave On date empty for today, or pick another day to see how old someone is or was then.
Handy to know someone's age on a particular day, for example for an application.
Fill in the fields; the answer appears here straight away.
How it's worked out
How it works
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Enter the values
Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.
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Instant answer
The answer appears as you type, with the most important intermediate values.
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See the working
Under "How it's worked out" you see the steps, handy for checking your own calculation.
Handy for
- Knowing exactly how old you are, or how many days you have been alive.
- Checking whether someone is 18, 21 or 65 on a particular date, for example for an application.
- A baby's age in weeks or months.
- The day of the week you were born and when your next birthday is.
How does it count?
First the calculator counts the whole months from the date of birth, then the days that are left. If you were born on the 31st and a month is shorter, the last day of that month counts. Someone born on 29 February turns a year older on 28 February in years without a leap day. To count the days between any two dates, including working days, use days between dates.
Different ways to say the same age
| Date of birth | On date | Age |
|---|---|---|
| 17 May 1990 | 17 May 2027 | 37 years |
| 31 January 1985 | 1 March 2026 | 41 years, 1 month, 1 day |
| 29 February 2000 | 28 February 2027 | 27 years |
The same person is also 15,004 days, 2,143 weeks and 3 days, or 493 months old in the second row. Choose the unit that the form or the milestone asks for.
Milestone dates
A baby's age is given in weeks and then months. Children's ages for school entry and sport leagues are given on a cut-off date, which you can enter as On date. Retirement and benefit ages depend on rules for the specific date of birth, so use this result as a check, not as a legal answer.
Roman numerals for fun
Want your birth year in Roman numerals? Try the Roman numeral converter, and for the number of days between two dates, days between dates.
Frequently asked questions
How is age in months counted?
Whole months from the date of birth to the chosen day. Someone born on 31 January 1985 is 41 years, 1 month and 1 day old on 1 March 2026, because the month counted from 31 January ends on the last day of February.
Can I find my age on a past or future date?
Yes. Fill in *On date*, for example the closing date of an application. Leave it empty for today.
When does someone born on 29 February have a birthday?
The calculator counts a birthday on 28 February in years without a leap day. For 29 February 2000, the person turns 27 on 28 February 2027.
How many days old am I?
The result shows the number of days, together with weeks and months. 15,004 days is just over 41 years.