Age Calculator – Calculate Your Age in Years and Days
Calculate your exact age in years, months, days and total days from a birth date.
About the Age Calculator
What is the Age Calculator?
An age calculator works out exactly how old someone is in years, months and days, along with their age in total days and time until their next birthday.
Why use this calculator?
Applications, medical forms and milestone planning often need a precise age rather than a rough number of years.
How to use it
- Enter the date of birth.
- Optionally enter the date to measure age at, or leave it blank for today.
- Read the exact age and the totals.
Formula
Age is counted in whole years, then remaining months, then remaining days, respecting month lengths and leap years.
Because months vary in length, the "months and days" figure can differ by a day or two from a simple division.
Frequently Asked Questions
Does it handle leap years?
Yes. The calculation uses the real calendar, so February 29 birthdays and leap years are handled correctly.
Why is my age in months different from age × 12?
Months are different lengths. The calculator counts complete calendar months since your birth, then the leftover days.
Does it account for leap years?
Yes. The date logic follows the Gregorian calendar, including leap years and differing month lengths.
Are weekends and holidays excluded?
Only if the calculator says so. By default, results count every calendar day; use a business-day option where available.
Which time zone is used?
Calculations use whole calendar dates and are time-zone independent unless a time-of-day is involved.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.
Is the information I type kept private?
Yes. All calculations run locally in your browser. Nothing you enter is uploaded, stored or shared with anyone.