# Age calculator

> An age calculator subtracts a date of birth from a chosen date and shows the gap in full years, months, and days. Someone born on March 15, 1990 is 36 years, 7 months, and 22 days old on November 6, 2026. The tool also reports total days lived and how many days remain until the next birthday.

Source: https://www.calterix.com/en-us/calculator/age/ · Updated 11/06/2026 · en-US

## How to calculate your exact age

Age in full years is the difference between the two years, minus one if the birthday has not come yet this year. The leftover months and days come from the gap between the dates, borrowing days from the previous month when needed.

The result is chronological age, counted from birth to the date you choose. With "Age on" set to today, you get your current age.

```
Age = "Age on" date − date of birth
Example: 03/15/1990 to 11/06/2026 = 36 years, 7 months, 22 days
```

For the gap between any two dates, use the [days between dates calculator](https://www.calterix.com/en-us/calculator/days-between-dates/).

## What an age calculator is for

- Check exact age for a school cutoff date, since kindergarten cutoffs differ from state to state.
- Find out how old someone is on a past or future date, such as the day Medicare eligibility starts at 65.
- See how many days are left until the next birthday.

## Frequently asked questions

### How do I calculate my exact age?

Subtract your date of birth from today's date. The calculator returns full years, months, and days.

### How do I find my age on a future date?

Type the future date into the "Age on" field. The calculator works out your age for that day.

### How many days old am I?

The summary under the result shows the number of days from your birth to the "Age on" date.

### How does age work for a leap day birthday?

For someone born on February 29, the next birthday in a non-leap year is counted on March 1 in this calculator.

### How do I find a premature baby's adjusted age?

Subtract the weeks the baby was born early (before 40 weeks) from chronological age. A baby born at 34 weeks and now 5 months old has an adjusted age of about 3 and a half months. Use this tool for chronological age, then confirm the adjustment with the pediatrician.

### How do I find how many weeks pregnant I am?

Gestational age counts weeks from the first day of the last period, not from birth. Use the [due date calculator](https://www.calterix.com/en-us/calculator/due-date/), which also gives the due date and accepts ultrasound results.