Age Calculator

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Exact age to the day. You can pick a custom “as of” date to compare to a past or future date.

About this age calculator

This page gives you a precise, human-readable breakdown of your age using real calendar math. Enter your date of birth and an optional “as of” date, then get your age in years, months, and days alongside total days and weeks. We also show the weekday you were born, your next birthday, how many days remain, and the age you’ll turn. Everything runs in your browser for speed and privacy.

Why does precision matter? Age shows up everywhere: milestone planning, school or visa cutoffs, benefit eligibility, fitness programs, even fun facts like “how many Mondays have I lived.” Unlike quick approximations that assume 30-day months, this calculator respects month lengths, year boundaries, and leap years so your results make intuitive sense. If you pick a future “as of” date, you can preview your age on that day to plan ahead. Need a record? Export a CSV of your inputs and results with one click.

Note: For official age verification, rely on government records or issuing authorities.

Dates

Required
Defaults to today
All calculations run in your browser.

Result

Age

Total days

Weekday of birth

Next birthday

How to use this age calculator

  1. Select your Date of birth.
  2. (Optional) Choose an As of date to compare age on a past or future day. If you leave it empty, we use today.
  3. Click Calculate. You’ll see your exact age in years, months, and days, plus total days and more.

Tip: Use Download CSV to save your results for records or planning.

What your result means

We calculate age using real calendar math between your birth date and the selected “as of” date. The Y-M-D breakdown respects month lengths and year boundaries. When a target month lacks the same day number (e.g., Jan 31 → Feb), we adjust to the last valid day to keep the calculation consistent.

This tool is for general information. For legal or official age verification, always use government records.

FAQ

Why do my months sometimes seem shorter or longer?

We follow real calendar boundaries. If a month doesn’t have the same day (e.g., 31st), we shift to the final valid day of that month.

Can I check my age on a future date?

Yes. Set the “As of” field to any date to see your age on that day.

How do leap years affect my next birthday?

If you were born on Feb 29, your next birthday falls on Feb 29 in leap years; otherwise we use Feb 28 by common convention.

What’s included in the CSV export?

We include your birth date, as-of date, Y-M-D age breakdown, total days/weeks/months (approx.), next birthday date/weekday, turning age, and days until next birthday.

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