The Center for Disease Control has a tool that can help you determine just how old your heart is.

Just because you're 40, doesn't mean your heart is 40. Certain risk factors like smoking, lack of exercise or poor diet can make your heart a lot older than you are.

No matter what your age, you need to take care of your heart. It's the hardest working muscle in your body, going non-stop your entire life. But it may not be the same age as you are if it's working too hard.

The CDC created a tool that can tell you just how old your heart is...and it could be the wake up call you need to get your health in check.

Here's how it works:

First you need to calculate your Body Mass Index (a measure of your body fat based on height and weight.)

Then you plug that number into the CDC's Heart Age Predictor Tool.

The resulting number is the age of your heart.

If that number is lower than your actual age...congrats you've got a pretty healthy heart!

If that number is higher than your actual age...you should think about ways to get your heart health in check.