Age Difference Calculator
Calculate the exact age difference between two people in years, months, and days from their birth dates.
Age Difference Examples
| Older birth date | Younger birth date | Difference |
|---|---|---|
| 01/01/1990 | 01/01/2000 | 10 years, 0 months, 0 days |
| 06/15/1990 | 06/15/1995 | 5 years, 0 months, 0 days |
| 01/31/2000 | 02/28/2000 | 0 years, 0 months, 28 days |
| 02/29/2000 | 02/28/2001 | 1 year, 0 months, 0 days |
| 01/01/2000 | 01/01/2000 | 0 years, 0 months, 0 days |
Frequently Asked Questions about the Age Difference Calculator
How do you calculate the age difference between two people?
Subtract the earlier birth date from the later one, then break the result into years, months, and days. The calculator uses calendar math, so it accounts for different month lengths and leap years. It also shows the total number of days between the two dates.
What is considered a big age gap in a relationship?
There is no universal threshold for a big age gap. The calculator reports calendar distance only. It does not measure compatibility, maturity, power dynamics, or relationship quality.
What is the half plus seven rule?
It is an informal dating guideline: the youngest age you should date is half your age plus seven. For a 40-year-old, that floor is 27 (40 / 2 = 20, plus 7). It dates back to the early 1900s and is a rough social heuristic, not a scientific rule.
Do age-gap relationships last?
An age difference alone cannot predict whether a relationship will last. The calculator performs date arithmetic and should not be treated as a relationship-risk model.
Does the order I enter the dates matter?
No. The calculator finds the older person automatically and reports the absolute difference, so you can enter the two dates in either order and get the same result.
Related Calculators
More calculators in "Date & Time"
Countdown CalculatorTime CalculatorTime Duration CalculatorTime Card CalculatorDay of Week CalculatorBirthday Countdown Calculator
See all 53 calculators in "Date & Time"