Is your heart older than the rest of you?

You know how many birthdays you’ve had. But how old is your heart?

Most U.S. adults have a “heart age” that’s older than they are, often by quite a bit, based on wear and tear, heart disease and lifestyle, according to research led by Northwestern Medicine. The study is published in the journal JAMA Cardiology.

Northwestern University has created a free online tool that calculates how your heart compares to your chronological age and risk for heart disease, using health data like cholesterol levels, smoking status, blood pressure and whether you have diabetes. They make a point, however, of noting it’s not intended to replace doctor visits and that you should use it in consultation with a doctor.