Age Difference Calculator
Find the exact age difference between two people from their birth dates in years, months and days, plus total days and weeks, who is older and both ages today. You can also estimate the gap from birth years only.
Age difference calculator
Age gap calculator by birth year only
How the age difference is calculated
The calculator counts whole years first, then whole months, then the remaining days, the same way you'd count a birthday. May 15, 1990 to August 20, 1994 is 4 years, 3 months and 5 days, or 1,558 days. With only birth years you can only say the gap is the difference in years, or one less for the part of the year between the two birthdays.
Age gap in relationships: the half-your-age-plus-seven rule
A popular rule of thumb says the youngest age someone "should" date is half their age plus seven: a 40-year-old's lower bound is 27. The calculator shows it for fun; it isn't a scientific or legal standard.
Age gaps that matter for money
- Social Security spousal benefits: a spouse can get up to 50% of the other's full-retirement-age benefit. A big age gap changes when it's best for each spouse to claim, and the survivor benefit lets the higher earner's benefit continue.
- Inherited IRAs: a beneficiary not more than 10 years younger than the owner can stretch withdrawals over their life expectancy instead of the 10-year rule (see the inherited IRA RMD calculator).
- RMDs: a spouse more than 10 years younger and the sole beneficiary lets the owner use the Joint Life table, giving smaller required distributions.
Common questions
How do I calculate the age difference between two people?
Subtract the earlier birth date from the later one, counting whole years, then months, then days.
What is the age gap between someone born in 1990 and 1994?
3 or 4 years depending on the birthdays; May 15, 1990 to August 20, 1994 is 4 years, 3 months, 5 days.
What is the half-your-age-plus-seven rule?
A rule of thumb that the youngest partner age is half your age plus seven. It's not a scientific standard.
How many days apart are two birthdays?
Enter both dates; the calculator shows the exact number of days.
Does an age gap affect Social Security?
It can change the best claiming ages for spousal and survivor benefits; the SSA's calculators help compare.
Sources
- Social Security Administration: Benefits for spouses
- IRS: Retirement topics, required minimum distributions
Related
General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.