Is this age calculator free?

Yes, completely free with no account required. All calculations run in your browser.

Does my date of birth leave my device?

No. Everything runs client-side in JavaScript. Your birth date is never sent to any server.

Does it work on mobile?

Yes. The tool is mobile-first and works in Safari and Chrome on iOS and Android.

How is the exact age calculated?

The calculator subtracts the birth date from the reference date accounting for variable month lengths and leap years, giving years, months, and remaining days. Total days is computed from the millisecond difference between the two dates.

年齢計算

年・月・日単位での正確な年齢と、次の誕生日までのカウントダウンを表示します。

Date of birth Age at date (default: today)

How to use

Enter your date of birth using the date picker.
Optionally set a reference date — leave blank to default to today.
Results appear instantly: age in years/months/days, total days lived, birthday countdown, day of week, and zodiac sign.

Related calculators

Date Difference Calculator — count days between any two dates
BMI Calculator — calculate Body Mass Index
TDEE Calculator — find daily calorie needs by age and activity

More age tools

How Old Am I? — instant answer with zodiac and day-of-week details
Exact Age Calculator — age to the day for any two dates

よくある質問

Is this age calculator free?: Yes, completely free with no account required. All calculations run in your browser.
Does my date of birth leave my device?: No. Everything runs client-side in JavaScript. Your birth date is never sent to any server.
Does it work on mobile?: Yes. The tool is mobile-first and works in Safari and Chrome on iOS and Android.
How is the exact age calculated?: The calculator subtracts the birth date from the reference date accounting for variable month lengths and leap years, giving years, months, and remaining days. Total days is computed from the millisecond difference between the two dates.

Last updated: 2026-05-20 By jarvisbox