Age isn't always calculated the same way around the world. This calculator uses the most common system — where age increases each year on your birthday. For example, someone who's been alive for 3 years and 11 months is still considered 3, and will turn 4 on their next birthday.
Some cultures count age differently. In certain traditions, like the Chinese age system, babies are considered 1 year old at birth, and their age increases not on their birthday, but at the Lunar New Year. So, a child born just a day before the New Year might be considered 2 years old just two days after birth.
Also, calculating months and days can sometimes be tricky — especially if your birthdate or today’s date falls at the end of a month. For example, from Feb 28 to Mar 31, some might say that’s 1 month and 3 days; others might simply say it’s 1 month. This tool follows the first approach — counting Feb 28 to Mar 28 as one full month, then adding extra days.
bmi
