Welcome to our versatile age calculator! This tool calculates your current age when you input your date of birth. You can use it to find out your age on a specific past or future date by entering that date in the ‘Your Birth Date’ field.
The output is displayed in years, months, and days.

Calculate the age of a person, place or thing. The age calculator calculates age given a date of birth in years, months and days. You can also use this calculator to find length of time between two dates.

The age calculator finds age in years, months and days, months and days, weeks and days, and in total days, total hours, total minutes, and total seconds.

How to Calculate Age

This age calculator uses two similar but slightly different methods to calculate age. One method calculates age in years, months and days, and also months and days. The other method precisely calculates age in total days only.

In the first method the age calculator finds age in common terms, calling all years equal and all months equal. The calculator finds the time between two dates in terms of generic years and months.

For example, a teenager might say he is 15 years old rather than saying he’s 12 normal years old plus 3 leap years old. This age calculator uses the same assumption — although we know years may have different lengths, we generalize between regular years and leap years, and call them equal.

The same is true for months. If a baby is 7 months old, the parents would not say she is 4 months that are 31 days long, plus 2 months that are 30 days long, plus 1 month that is 28 days long. We typically generalize across months of different lengths, and count them equal.

In the calculation for total number of days only, the calculator uses a function to find the precise number of days that have elapsed since a date of birth. This function calculates the number of regular years and also the number of leap years in the given time span.

Age in total number of days is calculated as:

• Number of years, x, with 365 days = 365 * x plus,
• Number of years, y, with 366 days = 366 * y plus,
• Number of days in the remaining partial year

The age calculator uses a function that recognizes how many leap years are in a given time span. It also calculates the specific number of days in a partial year. For example, if you were born on March 5 and today is June 7, the calculator finds the exact number of days that occur between those dates.

If you want to know how many days you’ve been alive you need to account for extra days in leap years. You also need to know the months with 31 days, those months with 30 days, and the month with 28 days.

List of Number of Days per Month

• January – 31 days
• February – 28 days in a regular year
• February – 29 days in a leap year
• March – 31 days
• April – 30 days
• May – 31 days
• June – 30 days
• July – 31 days
• August – 31 days
• September – 30 days
• October – 31 days
• November – 30 days
• December – 31 days

Date Inputs

The age calculator allows you to input single digit days. You do not have to pad them with a leading zero if the date is less than 10. You can input the 4-digit year, or use the date picker option.

This calculator assumes the start date is day 0 and begins counting one full day after day 0. For example if you input the dates 03/15/2022 and 3/18/2022 into the calculator you will get a total age of 3 days. Day 1 is the 16th, day 2 is the 17th, and day 3 is the 18th. The 15th is not counted in the tally of days.