How to Measure a Window Diagonal
We have a customer resource page full of advice on measuring, installing, or caring for your insert. Visit any time you have an issue.
We use our laser measurement tool to take 6 measurements of windows to make our custom window inserts so they have a precise fit. We custom cut each insert to ensure a Snug Fit that creates an airtight seal.
The diagonal measurement is always a little harder to take because you have to hold the laser measure tool at an angle rather than placing it against the window frame. That’s why we created the diagonal extension tool. The laser magnetically snaps onto the diagonal tool, which can be adjusted to any angle and tightened, then measure as usual.
Helpful tips for using the diagonal extension laser measure tool:
Make sure you're holding the button to create a triangle of resistance.
The feet of the tool don’t have rubber (for easy minor adjustments) so they can move when you click the laser’s button, changing the distance.
Use two hands on the laser measure tool.
This helps keep it steady when pressing the button.
Use a book to hold extension leg (black) in place.
Hold your finger on the laser measure tool button and keep your eye on the laser dot.
Place one finger on the base of the red leg and one on the button at all times.
Watch this video to get the finger placement down:
How to Measure for Window Inserts: We’re Experts
We know how to measure a window with our eyes closed—these tips come after years of experience. But, we’ve also helped a lot of people through this process and by the end of the first diagonal, they are a window measuring master.
Some other silly tips: Do yoga before you start measuring. You’re going to have to hold your hands in one corner and crane your neck to look in the other corner. Doing some light stretching isn’t a bad idea. Also, keep the laser button half depressed at all times so you’re ready to take that measurement. Think of it like that arcade game Cyclone. It has a circle of lights and you have to press the button right when it passes in front of you to get the prize. Having it already pressed halfway saves milliseconds! The same is true for measuring windows.
Laser Measure Tool Extension Inspired by You!
Our diagonal extension tool was inspired by a customer. They requested that we include a wedge to rest the laser tool on to make measuring diagonal easier. What we made was a wooden block with foam. But as anyone with older windows knows, not all window angles come in 90 degrees. Our tool evolved into the one we have now, which can be adjusted to any angle.
If you need any assistance measuring your windows, we’re here to help. And we’d love your feedback on the measuring process. You never know when you’re going to suggest our next measurement tool!
Want some more window measurement tips? Read these blog posts: What is a Frame Step? & Why We Laser Measure Windows.