Age Difference Calculator – Compare Two Birthdays Precisely

What this tool does. Enter two birthdays and the Age Difference Calculator instantly shows the precise age gap in exact years, months, and days. You also get the same difference expressed in total months, total days, hours, minutes, and seconds so you can see exactly how far apart two people are in age on a straight, easy-to-scan line.

How it works. The calculator compares Birthdate 1 and Birthdate 2 directly. It uses real calendar rules, including different month lengths and leap years, to compute the absolute difference between the two dates. It doesn’t assume who is older beforehand — it figures that out for you and clearly labels which person was born first.

All results in one line. The main result shows a clean phrase such as 3 years 2 months 14 days. Directly under it, the facts bar lays out the gap in months, days, hours, minutes, and seconds, plus a tag that tells you whether Birthdate 1 or Birthdate 2 is older. Everything is aligned in a single horizontal flow so you can screenshot or copy it without piecing numbers together.

Typical use cases. Use this for sibling age gaps, parent–child comparisons, coach and player eligibility checks, relationship age differences, or any context where you must confirm that an age gap meets a policy or personal preference. It’s especially handy for scholarship rules, sports brackets, school class cut-offs, or visa categories that mention “not more than X years older”.

Step-by-step. Choose the day, month, and year for Birthdate 1, then repeat for Birthdate 2. Click Calculate age difference to update the result instantly. To test another pair, simply change one or both dates and run it again — there’s no reset button cluttering the layout.

Connect with related tools. Once you know the gap, you can open the Age Calculator to see each person’s current age in detail, or use the How Old Was I Calculator and Weeks Between Dates Calculator to explore milestones and timelines built around their birthdays.

Accuracy & privacy. All calculations run directly in your browser using precise date logic. No birthdays are uploaded or stored on any server, so you can safely test real examples without sharing personal data.