International vs. Traditional Age
Did you know you might be 2 years older in East Asia? Different cultures count age differently.
Used by this calculator and most of the world. You are 0 years old when born. You age up on your birthday.
You are 1 year old at birth (accounting for time in the womb). Everyone ages up together on New Year's Day, not their birthday.
The "Leap Year" Problem
Calculating exact age is tricky because the calendar isn't perfect. A year is actually 365.2425 days long.
What is a "Leapling"?
A "Leapling" is a person born on February 29th. They only get a "real" birthday once every 4 years. In non-leap years, most legal systems consider their age to increase on March 1st.
Chronological vs. Biological Age
This tool calculates your Chronological Age (the amount of time passed since birth). However, your Biological Age depends on your health, genetics, and lifestyle.
- Chronological: Fixed. Increases linearly with time.
- Biological: Variable. Can accelerate with stress/smoking or decelerate with exercise/diet.
Frequently Asked Questions
Does this calculator count the end date?
Yes, in age calculation, the end date (today) is usually the milestone. If today is your birthday, you have completed that full year.
How many weeks have I lived?
We display this in the stats panel above! It is roughly Years × 52.176. Seeing your age in weeks (e.g., "4,000 Weeks") is a popular way to visualize life span (Memento Mori).