Enter two dates of birth to see exactly how far apart they are. Works for partners, siblings, parents and children — or any two dates, like the gap between two historical events.
The gap is counted like an age: whole years first, then whole months, then the remaining days. From 15 April 1990 to 2 November 1993 is 3 years (to 15 April 1993), 6 months (to 15 October 1993) and 18 days — 1,297 days in total.
When the later date’s day of the month is smaller, the months are counted back to the same day in the previous month, just as you would when working out someone’s age. Someone born on 29 February is treated as turning a year older on 28 February in non-leap years.
“Years (decimal)” divides the total days by 365.2425, the average length of a year in the Gregorian calendar.
Subtract the earlier birthday from the later one, counting whole years, then whole months, then days. This calculator does it exactly, including leap years and months of different lengths.
No — the difference between two birthdays is fixed. What changes is how big it feels: 5 years is a third of a 15-year-old’s life but a fifteenth of a 75-year-old’s.
Someone born on 29 February is counted as having their birthday on 28 February in non-leap years, which is the most common convention for ages.
Yes. Any two dates work — anniversaries, the gap between two historical events, or how much older one building or company is than another.
Month lengths vary, so “months and days” can be counted in slightly different ways. The total number of days is always the same and is the most precise figure.
