Everyday Tools
Age Calculator
- Browser-based
- No signup
Enter a date of birth and an optional calculation date to find age in years, months, and days, plus totals in months, weeks, and days. All calculations run in your browser.
100% Client-Side
Your data never leaves your computer.
How to use this tool
1. Enter a date of birth. 2. Optionally choose a calculation date; leave blank to use today. 3. Click Calculate age. 4. Review years, months, days, and total months/weeks/days in the results.
Worked example
Example: date of birth 15 March 1990 calculated on 1 January 2026 gives 35 years, 9 months, and 17 days.
When to use this
- Filling forms that ask for exact age in years, months, and days on a specific date.
- Checking school enrollment cutoff eligibility for a child on the district's reference date.
- Verifying retirement or benefits age against a policy's required birthday.
- Planning milestone birthdays or counting days until the next birthday.
Common examples
- Born March 15, 1990 → age on July 7, 2026 is 36 years, 3 months, 23 days.
- School cutoff Sept 1 → compare two children's ages on that date for kindergarten eligibility.
- Retirement planning → age in years and months on a target retirement date.
- Birthday countdown → days until next birthday from today's date.
- Form entry → exact age in years, months, and days for insurance or travel paperwork.
What people search for
Common mistakes
- Swapping day and month when entering dates in DD/MM versus MM/DD format.
- Using today's date when the form requires age as of a past or future reference date.
- Confusing total days lived with years multiplied by 365.
- Expecting fractional years to match years-months-days breakdown without calendar math.
Related long-tail tasks
- compare two people's ages on the same date
- calculate age on a future milestone date
- count days until next birthday
- verify kindergarten cutoff age for school district
- find age difference between two birth dates
How it works
The age calculator counts complete years, months, and days between the date of birth and the calculation date. It also reports totals in months, weeks, and days. All math runs locally in your browser.
Limitations
Counts calendar years, months, and days between dates. Does not account for time zones or leap-second adjustments.
Privacy and file handling
Your data is processed in your browser and is not uploaded to our server.
Specialized Age Calculator guides
Explore focused guides for common searches—each page reuses this age calculator with different examples and FAQs.
Frequently asked questions
How is age calculated?
Age is calculated from the date of birth to the selected calculation date by counting complete years, then remaining months, then remaining days.
Can I calculate age on a past date?
Yes. Leave the calculation date blank to use today, or choose any date on or after the date of birth.
Are future dates of birth allowed?
No. A date of birth in the future is invalid and will show an error.
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