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CALCULATORS

Age Calculator

Enter a birth date and a reference date to calculate exact age, total days lived, and days until the next birthday.

Tool statusRuns in your browser
Preview

Inputs

Results

Years
26
Months
7
Days
24
Total days
9,733
Days until next birthday
129

How it works

  1. Enter your input

    Fill in the values, paste your text, or upload the file this tool works with.

  2. See results instantly

    Most tools update live as you type; a few use a single button. Either way, the result appears right on this page.

  3. Use your results

    Copy, download, or share what the tool produces — you're always in control of the output.

Privacy and processing — Runs locally in your browser. This tool does not upload your input.

What is Age Calculator?

Calculate age from a birth date to any reference date in years, months, days, total days, and days until the next birthday.

UNDERSTAND THE TOOL

How to calculate exact age

How to use it

  • Enter the birth date.
  • Choose the date you want to calculate age on.
  • Read the exact age breakdown and total days.

Common uses

Age calculators are useful for forms, eligibility checks, birthday planning, school records, and quick date-of-birth calculations.

Reference date

Changing the reference date lets you answer questions such as age on an event date, age at the end of a school year, or age on a future deadline.

Worked example

Age parts
full years + full months since last birthday + remaining days

Born 2000-05-10, as of 2026-07-31

The age is 26 years, 2 months, and 21 days, plus the total day count between the two UTC dates.

Birthday notes

Age is calculated from calendar dates, so the result changes on the birthday and ignores the time of day.

Frequently Asked Questions

Can I calculate age on a past date?

Yes. Change the reference date to calculate age on that exact day.

Does it count total days lived?

Yes. The result includes total days between the birth date and reference date.

Can the birth date be in the future?

No. Future birth dates are treated as invalid input.

How are leap-day birthdays handled?

Dates are built in UTC and JavaScript normalizes impossible anniversary dates. Review leap-day cases manually if a legal or policy deadline depends on the exact birthday rule.

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