Everyday Calculators
Age Calculator — Exact Age in Years, Months & Days
Work out an exact age in years, months and days between any two dates — plus total days lived, the next birthday and the weekday of birth.
Open toolAge Difference Calculator
What is the exact age gap between two people — siblings, partners, a parent and child, or two historical figures? Enter both dates of birth into this free age difference calculator and it works out the difference in years, months and days, tells you which person is older, and shows the total number of days between the two births. It is the quick way to answer questions like "how much older is she than me?", to check the spacing between children, or to settle arguments about who is really the eldest. The calculation uses the real calendar, leap years included, and runs entirely in your browser.
Two dates of birth
How to use this tool
- Enter the first date of birth.
- Enter the second date of birth.
- Read the gap in years, months and days, plus total days.
- Use it for siblings, partners, eligibility checks and forms.
Worked example
Between 15 June 1990 and 20 November 1995 the gap is exactly 5 years, 5 months and 5 days — the second person is younger.
Frequently asked questions
How is the age difference between two people calculated?
The calculator subtracts the younger person's date of birth from the older person's, borrowing days and months the same way an exact age is worked out. The result is expressed in completed years, months and days — so a gap of "3 years, 4 months and 12 days" means the older person had already been alive that long when the younger one was born. The total-days figure is a straight count of calendar days between the two dates.
Does it matter which date of birth I enter first?
No. The calculator compares the two dates and always reports a positive gap, plus a line telling you whether the first or the second person is older. If both dates are identical it reports a difference of zero — the two people were born on the same day.
Can I calculate the age gap between a person and an event?
Yes — the second "date of birth" can be any date, not just a birthday. Enter a wedding date, a graduation, or the date a photo was taken to find how old someone was at that moment, or enter a future date to see the age gap at that point in time. For a single person's exact age on a given date, the age calculator is the more direct tool.
What is the average age gap between siblings?
There is no single "right" gap, but birth-spacing statistics in the US and Europe typically show a median gap of roughly two to three years between first and second children. Parents use this calculator to work out exact spacing for school planning, and genealogists use it to sanity-check birth records in a family tree — a gap of under nine months between full siblings, for example, usually means one of the dates is wrong.
Related tools: find one person's exact age with the age calculator, or a next-birthday countdown with the birthday calculator.