Free Age Difference Calculator
The exact age gap between two people.
What is the Age Difference Calculator?
Working out exactly how far apart two people are in age is fiddly by hand — months and days don't divide neatly, and leap years get in the way. This calculator does it precisely from two birth dates, giving the gap in years, months and days plus handy totals.
It runs entirely in your browser and the order of the dates doesn't matter.
Last updated: Aug 30, 2026
What does this tool do?
Enter two birth dates and it shows the exact age difference broken into years, months and days, along with the total number of months, weeks and days between them. It counts real calendar months and handles leap years, so the figure is accurate rather than a rough estimate.
It always shows the gap as a positive number, whichever date you enter first.
Key features
Exact gap
Years, months and days.
Handy totals
Also in months, weeks and days.
Order-independent
Enter the dates either way.
Leap-year accurate
Counts real calendar dates.
Private
Runs in your browser.
Example
Common use cases
- Couples — Find the exact age gap.
- Siblings — See how far apart you are.
- Parents — Compare children's ages.
- Genealogists — Work out gaps between relatives.
- Curious minds — Settle an 'how many years?' debate.
- Anyone — Compare two ages precisely.
Benefits
- Precise gap, not a rough guess.
- Extra totals for context.
- Works whichever date comes first.
- Free and private.
Tips
- Use the totals in weeks or days for very small gaps between babies or twins.
- The years-months-days figure is the most natural way to describe an age gap in conversation.
- It compares birth dates, not current ages — the gap stays the same over time.
- For a single person's age, use an age calculator instead.
- Enter full four-digit years to avoid any ambiguity.
Common mistakes to avoid
Expecting current ages
Fix: This shows the gap between two birth dates, which never changes — use an age calculator for someone's age today.
Worrying about date order
Fix: It doesn't matter — the gap is always shown as a positive difference.
Estimating months as 30 days
Fix: The tool counts real calendar months, so it's more accurate than a rough day-count.
Two-digit years
Fix: Enter the full year to avoid ambiguity.
How it works
- 1
Enter two dates
Both birth dates.
- 2
See the gap
Years, months and days.
- 3
Check the totals
In months, weeks and days.
Frequently asked questions
Enter both birth dates and the calculator shows the exact gap in years, months and days, along with totals in months, weeks and days.
No — the calculator always shows the gap as a positive difference, whichever date you enter first.
Yes — it counts real calendar months and days, so leap years are handled correctly.
Enter both birth dates and it shows the exact gap in years, months and days, plus totals in months, weeks and days.
No — the gap is always shown as a positive difference, whichever date you enter first.
Yes — it counts real calendar months and days, so leap years are handled correctly.
Yes — free, no sign-up.
Conclusion
Get the precise age gap between two people in years, months and days, with totals in weeks and days for context. It's leap-year accurate and order-independent — just remember it measures the gap between birth dates, which stays constant, not anyone's current age.