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Age Calculator

Age calculator

Find your exact age in years, months and days — or calculate the age between any two dates.

  • Exact age to the day
  • Total days, weeks and months lived
  • Days until next birthday
  • Works for any historical date
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Please enter a valid date of birth.
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What does this calculator work out?

Enter your date of birth and this tool calculates your exact age in years, months, and days — as of today or any date you choose. It also shows your total days alive, total weeks, total months, and the number of days until your next birthday.

If you need to count working days or plan around holidays, try our Days in Month calculator. For age-related mortgage term checks, use our mortgage calculator.

Why exact age matters

There are many situations where your age to the day matters more than just the year:

  • Legal eligibility: Driving, voting, pension access, and alcohol purchase all have specific age thresholds that depend on the exact date.
  • Mortgage terms: Most lenders require a mortgage to end before age 70–75 — knowing your exact age determines your maximum term.
  • Medical screening: NHS health checks and some prescriptions are triggered by specific age milestones.
  • Life milestones: Calculating exactly how many days until a 40th, 50th, or 100th birthday, or how many days a person has lived.

How dates are handled

The calculator uses your local device date by default. If you enter a custom "calculate on" date, it uses that instead. Leap years are handled correctly — a person born on 29 February has their birthday recognised on 28 February in non-leap years. All calculations run entirely in your browser; no date information is sent anywhere.

Results are for informational purposes only. For legal or financial decisions, always verify with the relevant authority.

Frequently asked questions

How is exact age calculated?
The calculator counts years from date of birth to today, then adjusts for the remaining months and days. If the current day of the month is before the birth day, one month is subtracted and the remaining days are carried across.
How are days until next birthday calculated?
The calculator finds the next occurrence of your birth month and day from today, then counts the days remaining — accounting for leap years. If your birthday is today, it returns the days until the following year's birthday.
What if I was born on 29 February?
In non-leap years, the birthday is treated as 28 February for the purposes of "days until next birthday". The age calculation in years is not affected.
Can I calculate the age between two dates?
Yes. Fill in the "Calculate age on" field with any target date. This lets you work out how old someone will be on a future date, or how old they were on a past one.
What is the earliest date I can enter?
The calculator accepts dates from 1 January 1900 onwards. For earlier dates, the day and total figures may not be accurate due to calendar reform differences.
Does it work for children and babies?
Yes. The result shows years, months, and days — so a child who is 2 years, 3 months, and 5 days old is shown precisely, which is useful for health visitor and GP records.
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