Runs entirely in your browser. Nothing you enter is sent anywhere.
How to use Age & Date Difference Calculator
- Choose Age from date of birth, or Days between two dates.
- Pick the two dates. The second date starts as today, read from your own device.
- Read the exact difference, the totals in months, weeks and days, and the next birthday or the number of working days.
How the difference is counted
The calculator first counts whole months from the first date, then the days left over. When the first date is the 31st and a later month is shorter, it lands on that month's last day, so 31 January to 1 March is 1 month and 1 day. Someone born on 29 February has their birthday on 28 February in years that are not leap years.
Working days count Monday to Friday and include both the start and end dates. Public holidays differ by state and company, so they are not removed; subtract them yourself.
Worked example
Born on 15 August 2000, on 16 October 2026 you are 26 years, 2 months and 1 day old. October 2026 has 22 working days (Monday to Friday).
Frequently asked questions
Is my date of birth stored?
No. Everything is calculated in your browser and nothing is sent or saved.
Why does my age in days differ from another site?
Some sites count the end date as well, or use the time of day. This calculator counts full calendar days between the two dates.
Can I use it for notice periods or project deadlines?
Yes. Use Days between two dates to get the total days and the Monday-to-Friday working days, then take out any holidays.