Date & Time
Age Difference Calculator
Calculate the exact age difference between two people in years, months, and days from their birth dates.
Birth dates
Age difference
Person 1 is 5 years older than Person 2
Exact gap: 5 years, 5 months, 14 days.
Years
5
Months
5
Days
14
Total days apart
1,991
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?
Research usually treats gaps of 0 to 5 years as small, 6 to 10 years as moderate, and more than 10 years as large. The number alone tells you little. Life stage, maturity, and shared values matter far more than the gap itself.
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?
A 2014 Emory University study found that larger gaps correlate with higher divorce risk, roughly 18% higher at 5 years and 39% higher at 10 years. That is a correlation, not a cause. Communication, financial stability, and shared goals predict longevity more than the gap does.
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.