Age Calculator
Calculate exact age in years, months and days, plus days until the next birthday.
🔒 Runs entirely in your browser — nothing is uploadedHow exact age is counted
Exact age is a calendar calculation, not just a number of days divided by 365. The usual method counts full years first, then full months after the most recent birthday, and finally the remaining days. For example, someone born on May 10, 2000 is 24 years old on May 10, 2024. On June 15, 2024, the same person is 24 years, 1 month and 5 days old. This calculator follows that calendar approach so the result matches how birthdays are normally described.
The page includes a Today field as well as the birth date. It defaults to your device's current date, but you can change it to answer questions such as “How old was someone on a historical date?” or “How old will this person be on a future date?” Results update immediately, and no date is sent anywhere.
Days until the next birthday
The next-birthday count looks for the birthday in the selected year. If that date has already passed, it checks the following year. The difference is shown in whole calendar days from the selected Today date. This is useful for planning reminders, invitations, eligibility windows or simple curiosity. Leap-day birthdays can be handled differently by different institutions; this browser-based calculator uses the local JavaScript Date behavior, so confirm official deadlines when February 29 matters.
Private date math in your browser
Birth dates can be sensitive personal information. Calc Tools does not upload them, create an account profile or call an external age service. The script reads the date fields, performs the calendar math locally and writes the answer back to the page. Use the result for everyday planning, forms and quick checks. For legal, medical, school or immigration purposes, verify the date rules required by the relevant organization because cutoffs may depend on local law or policy rather than a general-purpose age formula.
How to use
- Enter a birth dateChoose the date of birth using the date picker or type it directly.
- Check exact ageThe calculator shows completed years, months and days as of today.
- See next birthdayRead how many days remain until the next birthday.