Online Tool Store
Age Calculator
Calculate exact age in years, months, and days, see total weeks and days, and count down to the next birthday. Free and private in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How the age calculator works
- Enter a date of birth and the date on which you want to measure the age.
- The calculator counts complete calendar years and months, then adds the remaining whole days.
- It also shows complete months, total weeks and days, the birth weekday, and the next birthday.
- Total days are also converted to hours, minutes, and seconds for a full lifespan breakdown.
- Use the "Copy results" button to copy the full breakdown as text, ready to paste anywhere.
The method
Age is a calendar interval, not an average number of days divided by 365. The calculator first finds the greatest whole-month anniversary that does not pass the target date. It converts every 12 complete months into a year, then counts the days from that anniversary to the target date.
exact age = complete years + remaining complete months + remaining days
Example: from June 15, 1995 to August 13, 2026 is 31 years, 1 month, and 29 days. Total-day and week figures use the actual elapsed calendar days, including leap days.
FAQ
How is exact age calculated?
The calculator counts complete calendar months from the birth date to the target date, then counts the remaining whole days. Twelve complete months are displayed as one year.
Does the calculation account for leap years?
Yes. Total days are calculated with real calendar dates, so leap days are included automatically. For a February 29 birthday, February 28 is used as the birthday in non-leap years.
Can I calculate age on a past or future date?
Yes. Change the Age on field to any date on or after the date of birth to calculate the age on that specific day.
Why can total months differ from years multiplied by 12?
The complete-month total includes both the full years and the additional completed months. Partial months are shown separately as days and are not rounded up.
Are my dates stored or uploaded?
No. The calculation runs entirely in your browser. Your birth date and target date are not sent to Online Tool Store or any other server.
How we compare
| Feature | Online Tool Store | Calculator.net | CalculatorSoup | Omni Calculator |
|---|---|---|---|---|
| Calendar age in years, months, and days | ✓ | ✓ | ✓ | ✓ |
| Total weeks and days | ✓ | ✓ | ✓ | ✓ |
| Full breakdown in hours, minutes, and seconds | ✓ | ✓ | ✓ | ✓ |
| One-click copy of the full result as text | ✓ | Not offered | Save link instead | Share link instead |
| Updates instantly as dates change | ✓ | Calculate button | Calculate button | Not confirmed |
| Birth date stays in this browser tab | ✓ | Not stated | Not stated | Not stated |
Choose the Online Tool Store Age Calculator for a fast, focused result that updates as you type, breaks total time down to the second, copies to your clipboard in one click, and keeps the dates entirely on your device.