Age calculator and date difference calculator
Find an exact age in years, months and days, or count the days, weeks and months between any two dates.
Age calculator
Today by default. Change it to check an age limit on a cut-off date.
- Age
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- Total months
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- Total days
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- Next birthday
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Days between two dates
- Total days
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- Weeks and days
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- Years, months, days
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How to use the age calculator
- Enter a date of birth. The age on today's date appears straight away.
- To check an age limit, change Age on this date to the cut-off date in the admission or job notice.
- To count days, enter a start and an end date in the second calculator. Tick Include the end date if both the first and last day should count.
How the calculation works
Whole years and months are counted on the calendar first, then the remaining days. For example, from 15 January to 10 March is 1 month and 23 days in a non-leap year (15 January to 15 February is one month, then 15 February to 10 March is 23 days).
People born on 29 February have their birthday counted on 28 February in years that are not leap years. Some organisations count it on 1 March instead, so check their rules.
Worked example
Countdown to an exam
From 22 October 2026 to 1 March 2027 is 130 days, which is 18 weeks and 4 days.
Questions and answers
- Does it use my time zone?
- Dates are treated as whole calendar days, so time zones and daylight saving changes do not affect the result.
- Is my date of birth saved?
- No. The calculation happens in your browser. Nothing is stored or uploaded.
- Why might my age differ from an official document?
- Some rules round ages differently or use a specific cut-off date. Use the cut-off date from the official notice in the second date box.