Getting ready to replace your sliding glass door? Hold up—accurate measurements are the secret sauce to a perfect fit and a stress-free installation. In this ultimate guide, we’re sharing our professional measuring techniques to make sure your new door slides in like a dream.

We’ll walk you through step-by-step, from measuring the frame to checking for wonky walls or uneven floors. Our team’s learned the hard way what happens when measurements are off (spoiler: it’s not pretty), and we’re passing on our best tricks to save you headaches. Plus, we’ll cover tools you need and common mistakes to avoid, like forgetting to account for the track.

Grab a tape measure and let’s get those measurements spot-on for your sliding glass door replacement!