Gregorian calendar age for personal and planning use. For official legal or immigration verification, confirm with the issuing authority.

Skip to age calculator

Age Calculator — Calculate Your Exact Age

Enter your date of birth to see how old you are in years, months, and days. Optionally set any past or future date for “age as of,” then check days lived and next birthday—all in your browser, no signup.

Loading age calculator…
By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026-09-12· Reviewed by EverydayTools Editorial Team

What is an age calculator?

An age calculator turns a date of birth into exact chronological age—years, months, and days—as of today or any date you choose.

People usually say age as a whole number of years. Exact age is the calendar breakdown: completed years, then leftover months, then leftover days since the last birthday. That is the figure used on forms, school cutoffs, and everyday “how old am I?” questions.

This page starts from your date of birth and a reference date (today by default). It returns years, months, and days, plus total days lived and a next-birthday countdown. Change the reference date to answer “how old was I on…” or “how old will I be on…”.

Math runs in your browser. Birth dates are not uploaded to EverydayTools servers. For official eligibility, confirm the rule with the relevant authority—local laws can differ.

Enter a date of birth → get exact age in years, months, and days (today or any date).

How to calculate your exact age

  1. Enter your date of birth

    Pick your birth date. That is the only required input for “how old am I today?”

  2. Set an age-as-of date (optional)

    Leave blank for today, or choose any past or future date. Use presets for next birthday, New Year, five or ten years ahead, or your 18th birthday.

  3. Read years, months, and days

    The primary result is chronological age. Below it: total days lived, weeks, months, and a next-birthday countdown.

  4. Copy, share, or compare

    Copy or share the result. To compare two people, use Age difference mode here or open the dedicated Age Difference Calculator.

What this calculator answers

How old am I?

Enter your date of birth and leave the reference date empty (today). The hero result is your exact age in years, months, and days.

Calculate age from date of birth

DOB is the starting point. The calculator subtracts birth date from the reference date with real month lengths and leap years—not year-minus-year alone.

Age on a specific date

Set the reference date to any past or future day to answer “how old was I on…” or “how old will I be on…”. Useful for events, school cutoffs, and planning.

How many days / weeks / months old am I?

After you enter a birth date, total days lived (and weeks/months/hours) appear under the exact-age result—including leap days.

Next birthday countdown

See days until the next anniversary, the weekday it falls on, and the age you will turn. February 29 births use February 28 in non-leap years on this page.

Age 18 / eligibility as of a date

Set the reference date to the eligibility day (or use the “18th birthday” preset). If years ≥ 18 and the birthday has been reached on that date, an 18+ threshold is met in most places—confirm local rules.

age calculator examples

Exact age from date of birth

Input

Birth date: March 15, 1990 · Reference: May 2, 2026

Output

36 years, 1 month, 17 days

Count completed birthdays (36), then months after March 15 (1), then leftover days (17).

How old will I be on a future date?

Input

Birth date: March 15, 1990 · Reference: January 1, 2030

Output

Age in years, months, and days on that day

Change only the reference date; the same calendar math applies.

Checking age 18 as of a date

Input

Birth date: May 3, 2008 · Reference: May 2, 2026

Output

17 years, 11 months, 29 days — not yet 18

The 18th birthday is May 3, 2026. On May 2 they are still 17. Confirm eligibility rules with the issuing authority.

How exact age is calculated

Exact age uses calendar subtraction: whole years first, then whole months, then leftover days, borrowing when a day or month would go negative. Total days lived is a separate count of every calendar day between the two dates (including February 29 in leap years).

Formula

Years/months/days = calendar subtraction with month/day borrowing
Total days lived = calendar day count from birth date through reference date

Assumptions

  • Gregorian calendar for modern dates.
  • Empty reference date means today (device local date).
  • February 29 next-birthday dates use February 28 in non-leap years.

Limitations

  • Not a legal or medical age certificate—authorities may apply different rules.
  • Pre-Gregorian historical dates may not match archival calendars.
  • For a dedicated two-person age gap, prefer the Age Difference Calculator.

Exact age vs days lived vs next birthday

Different questions need different outputs.

OutputAnswersExample search
Years, months, daysChronological agehow old am I
Total days livedDay count since birthhow many days old am I
Next birthdayCountdown to anniversarydays until my birthday
Age as of dateAge on a past/future dayhow old will I be on

Which EverydayTools page to use

Pick the tool that matches the job.

ToolBest for
Age Calculator (this page)One person’s exact age, age as of a date, days lived, next birthday
Age Difference CalculatorGap between two birth dates or people
Date CalculatorAdd/subtract days or days between dates
Pet Age CalculatorDog or cat years → human-equivalent age

Common mistakes to avoid

Subtracting only the birth year

If your birthday has not happened yet this year, you are still one year younger than (current year − birth year).

Treating total days as the same as years

Days lived is a raw count. Forms usually want years, months, and days.

Expecting a February 29 anniversary every year

In common years this page treats the next birthday as February 28. Year counts still advance correctly.

When this tool isn't the right choice

You need the gap between two people

Use the Age Difference Calculator for a clear two-DOB comparison.

You need official legal verification

This tool is for personal and planning use. Confirm with the relevant authority.

You only need to add days to a date

Use the Date Calculator for add/subtract and days-between modes.

What to do next

Continue the workflow with the right follow-up tool.

Advertisement

Common questions

How do I calculate my exact age?

Enter your date of birth. Leave the age-as-of date empty for today, or pick any date. The result is years, months, and days using Gregorian calendar borrowing.

How old am I today?

Enter your date of birth and keep the reference date as today. You will see completed years, months, and days—your chronological age right now.

Can I calculate age from date of birth?

Yes. Date of birth is the required input. Everything else (days lived, next birthday, age on a date) builds from that DOB.

Can I calculate age on a specific date?

Yes. Set the reference date to the day you care about—past or future. The years/months/days result is your age as of that date.

How many days old am I?

Total days lived appears under the exact-age result. It counts every calendar day from birth through the reference date, including leap days.

How many days until my next birthday?

The next-birthday section shows days remaining, the date and weekday, and the age you will turn.

Does this handle leap years and February 29?

Yes for day counts and age math. For February 29 births, next-birthday timing uses February 28 in non-leap years (common U.S./U.K. convention). Year counts are unaffected.

How do I check when someone turns 18?

Enter the birth date and use the “18th birthday” preset, or set the reference date to the eligibility day. Confirm local eligibility rules—this is not legal advice.

Can I calculate age difference between two people?

Yes—use Age difference mode on this page for a quick gap, or open the Age Difference Calculator for a dedicated two-person tool.

Is the age calculator free?

Yes. Free, no signup, no account.

Is my date of birth uploaded?

No. Calculation runs locally in your browser. Birth dates are not sent to EverydayTools servers.

Privacy and accuracy

Privacy

Birth dates and reference dates stay in your browser for normal use—they are not uploaded to EverydayTools servers.

Accuracy

Uses Gregorian calendar rules including leap years; February 29 next-birthday timing uses February 28 in non-leap years on this page.

How this tool works

Exact age is derived locally from date of birth and the reference date.

For personal and planning use—not legal, medical, or official identity verification. Confirm eligibility rules with the relevant authority.

Advertisement

Reviewed by EverydayTools Editorial Team on 2026-09-12.

Related tools

Same workflow or intent — pick the next step without leaving the site.

Age on Other Planets Calculator

Enter your birth date to see your age on Mars, Mercury, Jupiter, and every planet—plus Earth days lived and your next planetary birthday. Free, private.

Pet Age Calculator: Dog & Cat Years to Human Years

Calculate your dog or cat's age in human years using age, months and dog size. See a quick age comparison, life stage and conversion instantly in your browser.

Age Difference Calculator — Calculate the Exact Age Gap

Enter two birthdays to see who is older and the exact age gap in years, months, and days—plus how many days apart. Free, private, no signup.

Date Calculator — Add, Subtract & Days Between Dates

Add or subtract days, weeks, months, or years from any date. Days-between mode included. No upload—runs locally in your browser. Free, no signup.

Employee Hours Tracker

Track employee work hours, unpaid breaks, overtime, and weekly timesheets for multiple employees. Optional pay estimates. Runs in your browser—no signup.

Freelance Hours Calculator

Calculate freelance hours, billable time, and earnings from your hourly rate. Track breaks and multiple sessions in the browser — no signup.

Popular in this category

Frequently opened tools from the same category.

Date Calculator — Add, Subtract & Days Between Dates

Add or subtract days, weeks, months, or years from any date. Days-between mode included. No upload—runs locally in your browser. Free, no signup.

Unix Timestamp Converter

Convert Unix timestamps (epoch time) to dates and dates to Unix timestamps. Seconds, milliseconds, UTC, local time, and ISO 8601. Runs in your browser.

Hours Calculator

Calculate hours between two times or dates. See hours, minutes, and decimal hours, including overnight spans. Runs in your browser — times are not uploaded.

Age on Other Planets Calculator — How Old Would You Be on Mars?

Enter your birth date to see your age on Mars, Mercury, Jupiter, and every planet—plus Earth days lived and your next planetary birthday. Free, private.

People also use

Cross-category tools others open in the same session.

Percentage Calculator

What is 20% of 500? Percent increase, decrease, difference, reverse %, markup & margin—runs locally in your browser, no upload. Copy results or share a link.

JSON Formatter

Free JSON formatter — paste minified or messy JSON and instantly get beautified, indented output with syntax highlighting and error detection. Browser-based, no server upload. Runs locally in your browser when supported—no upload required for normal use.

Word Counter

Free word counter — live word, sentence, and paragraph counts plus reading time for essays, blogs, and SEO drafts. Runs locally in your browser.

BMI Calculator

Free adult BMI from height and weight (lb/ft/in or kg/cm). CDC category, healthy weight range, optional waist. Screening only—runs in your browser.

Explore categories

Browse full tool collections by topic.

Date & Time ToolsCalculator Tools