Age Difference Calculator
Calculate the exact age gap between two people's birth dates, in years, months, and days.
Recommended Settings
Pro Tips
- •The order you enter the two dates doesn't matter - the calculator automatically figures out which is earlier
- •The years/months/days breakdown accounts for varying month lengths for a precise result
- •Total days apart is useful for quick comparisons or when you need a single number rather than a breakdown
- •This compares birth dates only - it doesn't account for the specific time of day either person was born
Most Popular
Most users compare sibling or partner birth dates to check the age gap in years and months
When to Use This Tool
Find the exact age difference between two siblings' birth dates.
Calculate the age gap between two partners.
Check the exact age difference for a rule or requirement based on relative ages.
Compare birth dates of family members while researching genealogy.
How It Works
Determine which of the two entered dates is earlier
Calculate the difference between them in years, months, and days, adjusting for varying month lengths
Also calculate the total number of whole days between the two dates
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Client-side calendar date arithmetic for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
Does the order I enter the dates matter?
No, the calculator automatically determines which date is earlier and calculates the difference accordingly.
How is the years/months/days breakdown calculated?
It accounts for the actual number of days in each calendar month between the two dates, rather than using a simplified average.
Is my data sent to a server?
No. The calculation happens entirely in your browser.
What's the difference between this and Age Calculator?
Age Calculator finds one person's age as of a specific date. This tool instead finds the gap between two different birth dates.
Can I use this for dates other than birthdays?
Yes, though for a general date-to-date difference not related to age, the Date Difference tool may be more clearly labeled for that purpose.