A home’s front door may be one of its most important features. Not only is it the gateway into your personal space and one of the defining factors of your exterior curb appeal, it’s also a crucial structural detail that needs to be strong enough to withstand outdoor elements like heat, wind, and ice. So when you’re choosing a new one, it’s important to consider both looks and utility—and to have a proper understanding of front door sizes and how to pick out the right fit.

 To help you out, we’ve put together this quick ex-plainer on the various factors that you’ll want to keep in mind as you seek out your perfect front door.