How is my age calculated in years, months, and days?

Age is calculated by subtracting your birthdate from the target date, borrowing days from the previous month and months from the previous year when subtraction yields negative values.

How many days have I lived?

To find the total days lived, calculate the difference in milliseconds between your date of birth and today, then divide by the number of milliseconds in a single day (86,400,000).

Age Calculator

Calculate your exact age in years, months, and days, count total days lived, and see a countdown timer to your next birthday.

Date of BirthAge at Date

Exact Age31 years, 0 months, 8 days

Days to Next Birthday357 days

Total Days Lived11,331 days

How to calculate age exactly

Compare your birth date with a target date (usually today). Subtracting the years, months, and days dynamically accounts for varying month lengths and leap years to return an exact chronological duration.

Total days lived vs years

While years give a high-level summary of your age, tracking total days lived gives the absolute count of days since your birth, incorporating all leap years (extra days in February) along the way.

Frequently asked questions

How is exact age calculated?

chronological age subtraction compares year, month, and day values, borrowing from the month's days when target days are less than birth date days.

How do I find out how many days I have lived?

Find the absolute millisecond difference between your birthdate and today's date, then convert that duration to days by dividing by 86,400,000 (the milliseconds in 24 hours).