Age Difference Calculator
Find the exact gap between two dates expressed in years, months and days, useful for ages, service length or event spans.
Recent
Formula
How the calculation works
Enter the earlier date and the later date, then choose whether to count complete calendar units or every single day.
The tool works from the earlier date forward, taking full years first, then full months, then the remaining days.
It returns the gap as separate year, month and day figures, so you see both the large unit and the small remainder.
Common mistakes
- Counting the start or end day twice, because inclusive counting adds an extra day and shifts the whole result by one.
- Swapping the two dates, since the later date must sit after the earlier one for the day and month remainders to make sense.
When to use it
- Use it to work out the exact age gap between two people when you want more than a rough year count.
- Use it to measure service length or the span of an event down to the day.
Worked example
From 15 May 1990 to 20 August 2020 the difference is 30 years, 3 months and 5 days, counting the months and days left after the full years.
Common questions
Does the age difference include the end date?
No, the calendar method counts the time elapsed between the two dates, so the end date itself is not added as an extra day.
Related tools
-
Discount Calculator
See what you actually pay after a discount, and how much you save.
-
Tip Calculator
Add a tip to the bill and split it between people.
-
Add Tax / VAT Calculator
Add tax or VAT to a price to get the total.
-
Percentage Calculator
Find what percentage one number is of another.
-
Percentage Change
How much a number rose or fell between two points.
-
Monthly Budget Split
Divide monthly income into needs, wants and savings.
-
Profit Margin & Markup
Profit, margin and markup from a cost and a selling price.
-
Original Price from a Sale
Work back from a discounted price and the discount rate to the original.