Age Calculator

Use our free age calculator to compute exact age from any birth date to any as-of date. Shows years, months, days, total days, hours, minutes, seconds, days until next birthday, and the day of the week you were born.

Math

Birth Date (YYYY-MM-DD)

As of Date (YYYY-MM-DD)

Formula

Calculate exact age from birth date to any as-of date. The calculator correctly handles month boundaries, leap years, and provides a comprehensive breakdown including total days, hours, minutes, seconds, and days until the next birthday.

Age = AsOf − Birth, adjusted for month/day boundaries

Percentage: The percentage value you want to apply

Number: The original number or value

Result: The calculated result

How It Works

1Enter your birth date.
2Enter the as-of date (defaults to today).
3Click Calculate.

Examples

Born Jan 1, 1990 to today

1.2026 − 1990 = 36 years, then adjust months and days

Result: 36 years, 6 months, 14 days

Frequently Asked Questions

Subtract years, then months, then days. If the birth day-of-month is greater than the as-of day, borrow from the previous month.

Yes — February 29 is handled correctly, and February is treated as having 28 or 29 days depending on the year.

The calculator will show an error since age cannot be negative.

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CalculateMe Team

Last updated: 2026-07-15

Age Calculator

Formula

How It Works

Examples

Born Jan 1, 1990 to today

Frequently Asked Questions

How is age calculated?

Does it handle leap years?

What if the as-of date is before the birth date?

Related Calculators

Age Calculator

Formula

How It Works

Examples

Born Jan 1, 1990 to today

Frequently Asked Questions

How is age calculated?

Does it handle leap years?

What if the as-of date is before the birth date?

Related Calculators