How is age difference calculated?

Subtract the birth years. The exact difference also accounts for dates.

What is the age difference calculator for?

E.g. finding the gap between siblings, partners or historical figures.

Age Difference Calculator

Name: Age Difference Calculator
Author: Miikka

Calculate the age difference between two people in years, months and days from birth years.

By Miikka · CalcBrew · Updated Jun 30, 2026

Person 1 birth year: 1,990

Person 2 birth year: 1,995

5 years

Age difference

Age difference in years	5 years
In months	60 months
In days (approx)	1,825 days

ℹ️ Calculated from birth years. The exact difference also depends on the birth dates.

The age difference calculator tells you how large the gap between two people is in years, months and days. Enter both birth years and you get the difference instantly in three different units.

How the calculator works and what it’s for▾

How the age difference is calculated

The age difference is found by subtracting one person's birth year from the other's. The calculator also converts the year gap into a rough estimate of months and days.

For example, people born in 1990 and 1995 have an age difference of five years, or about 60 months.

What you enter and what you get

You enter two people's birth years. The result shows the age difference in years, months and approximate days.

Three units side by side illustrate the gap in different ways, depending on whether you want the big picture or a more precise figure.

When to use it

The calculator suits satisfying curiosity between siblings, partners or friends, as well as genealogy where generations are compared. It's a quick tool whenever an age gap interests you.

It is also handy for organising a family tree and memories.

Good to know about accuracy

The result is based on birth years alone, so the real age difference also depends on the birth dates. For people born in the same year, the gap can swing nearly a year either way.

The number of days is an approximate estimate, since it doesn't account for exact dates or leap years. For an exact difference you need the full birth dates.

🔄 Reviewed June 2026

Frequently asked questions

Cite this calculator

APACalcBrew. (2026). Age Difference Calculator. https://calcbrew.com/age-difference-calculator

MLA“Age Difference Calculator.” CalcBrew, 2026, calcbrew.com/age-difference-calculator.

Link to https://calcbrew.com/age-difference-calculator. Results are estimates; cite the underlying formula or data source for academic work.