Age Gap Calculator
The age gap between two partners in years, months and days – and what the “half your age plus seven” rule says about it.
The age difference
Enter both birth dates. The calculator gives the exact gap in years, months and days and the number of days between the two birthdays. Example: born on 2 March 1988 and 20 November 1996 – an age gap of 8 years, 8 months and 18 days (3,185 days).
The “half your age plus seven” rule
A rule of thumb for the youngest partner that is socially accepted:
youngest = your age ÷ 2 + 7 and, the other way round, oldest = (your age − 7) × 2
For a 38-year-old that means at least 26; for a 29-year-old, at most 44. The rule appeared in print in the early 20th century and is a social convention, not science – and it only makes sense between adults.
How common are age gaps?
In most couples the gap is small – a few years, with the man more often the older one. Gaps of ten years or more are much less common. What matters more than the number are shared values and life stage.
Frequently asked questions
What is the half your age plus seven rule?
The youngest partner considered socially acceptable is half your age plus seven years; the oldest is double your age minus 14.
How do I calculate the age difference between two people?
Subtract the earlier birth date from the later one – the calculator does it in years, months and days.
Is a 10-year age gap a lot?
It is less common, but the rule of thumb accepts it from about age 34 (for example 34 and 24).