Instant Calculator

Exact age in every unit

Age Calculator - Years, Months, Weeks, Days, Hours & Seconds

Drop in a birth date and choose an as-of date (today or a future year) to see a clear age breakdown. The age calculator keeps numbers readable across years, months, weeks, days, hours, and seconds for real forms, travel plans, or fun trivia.

Age Calculator

Enter a birth date and pick an as-of date to see age in years, months, weeks, days, hours, and seconds.

Date of birth

No future dates allowed.

As of date

Use today or any past/future date.

Popular quick answers

Open with dates filled in, then adjust to your own

What is my age if I was born in 1988?

DOB prefilled: 1988-01-01

What is my age according to date of birth?

DOB prefilled: 1995-06-15

How old is my child in months today?

DOB prefilled: 2023-01-01

How old is my child in weeks?

DOB prefilled: 2024-05-01

How old will I be in 2040?

As-of date prefilled: 2040-01-01

Tip: change the asOf=YYYY-MM-DD part of the link to target any year (e.g., 2035-06-30) for programmatic SEO and future-age questions.

How the age math works

Leap-year aware, month-by-month math for clear totals

We compare your birth date and the as-of date in UTC, count full years first, then leftover months and days using each month's actual length. Remaining time becomes totals in weeks, days, hours, and seconds so you see both the biggest and smallest units side by side. It works the same for today or any future date, so you can answer questions like how old will I be in 2040?

Handles leap years and months with 28-31 days automatically.
Guards against dates in the future so results stay grounded.
Formats large numbers with separators to keep long totals readable.

For a quick check like "what is my age if I was born in 1988?" or "how old is my child in months and days?", enter the birth date, leave the as-of date on today, and press calculate.

Age formula, step by step

Turn dates into clear numbers you can share

Here is the manual process the age calculator runs when you ask about any birth year or future date.

Count full years between the birth date and the as-of date.
Count remaining months using each month's actual length.
Count leftover days after the last full month.
Convert the total time span into weeks, days, hours, and seconds for big-number views.

Try it with a prompt like "what is my age if I was born in 1990?" or "how old will I be in 2040?": set the birth and as-of dates, click calculate, and copy the formatted totals for forms or trivia.

For parents & caregivers

Answer kid-focused questions fast

Quickly answer the classics: how old is my child today? or how old is my child in weeks? The months-and-days view lines up with pediatric charts, while the weeks view helps with feeding or sleep schedules.

Need a month-based answer for school forms or passports? Enter the birth date and copy the months or days row directly.

For paperwork & timelines

Dates for HR, visas, and milestones

Eligibility checks, benefits windows, or a quick age check before a deadline rely on precise time spans. Use the weeks, days, and hours totals when you need the most granular number for audits or trivia.

Wondering your age on a specific date for a form or visa? Set the as-of date to that deadline to avoid cutoff surprises.

Common scenarios

Try these quick prompts inside the calculator:

Born in the late 80s or 90s? Enter your birthday and click calculate to get your exact age today.
Students and kids? The weeks and days view makes it easy to share ages for school, sports, or pediatric forms.
Planning ahead? Set the as-of date to any future day (e.g., 2040-01-01) to see how old you will be for timelines, visas, or milestones.
Need Korean age? This age calculator shows international age; add one year if you use the traditional Korean counting.

Frequently asked questions

How accurate is the seconds result?

We calculate using UTC to avoid daylight savings jumps. Seconds come from the full millisecond difference, then roll up into hours, days, and weeks for a clean view.

Can I check someone else's age?

Yes. Enter their birth date and set the as-of date; the age calculator returns the same breakdown in years, months, weeks, days, hours, and seconds.

Does it work for future dates?

Yes. Set any future as-of date (for example 2040-01-01) to see how old you will be for deadlines, visas, or milestones.

Can I save or share the result?

Copy the summary line with years, months, and days or screenshot the grid. The large-number formatting keeps totals readable on small screens.

Can it guess my age?

No. The age calculator uses dates you provide. It runs in your browser without sign-up or downloads.

Need more than an age calculator?

Browse our Other calculators for more date and time tools as we add them. Tell us which age calculator features you want next, and we will prioritize them.

Age Calculator - Exact Age in Years & Months