A window installer demonstrates how to measure replacement windows.

How to Measure Replacement Windows

Measuring replacement windows requires precision. For that reason, it’s not recommended for the casual DIYer. But for people with some carpentry skills, it can be done. To help, our team at Clearwater Exteriors, located in Denver, Colorado, wrote this how-to guide for measuring replacement windows. That said, if you are even the slightest bit unsure of your skills, it’s best to call the professionals and request a free quote. Our installers take accurate measurements and ensure accurate results. Keep reading to learn how to measure your replacement windows. 

Why Replacement Windows?

Replacement windows are an excellent option if you are looking to weatherize or improve the energy efficiency of your home or business. In many cases, they can also boost the resale value of your property. 

Write Everything Down

It sounds simple enough, but this step is one many people take for granted. Don’t trust yourself to keep the measurements tucked away in your head, even if you think you have a great memory. 

Why? Because when it comes to measuring replacement windows, precision and accuracy matter. We recommend writing each measurement in a notebook and also saving a file on your computer or phone with the measurements as a backup. We can’t stress this enough — accurate measurements are essential in the replacement window process. 

Make sure to label each window in your notebook so you don’t get confused. For example, devote a row for your kitchen windows, a row for your living room windows, a row for your bedroom windows, etc. That way, you will keep all of your measurements organized.  

Know the Shape

Windows come in all shapes and sizes. But we don’t recommend DIY measurements for replacement windows for all shapes other than squares or rectangles. 

Why? It’s because the measurements for rectangles and squares are relatively easy compared to other shapes. But when it comes to custom window shapes like circles, the formulas for calculating the measurements are more complex. And let’s face it — most people haven’t studied geometry since their math classes in high school!

For measurements of windows with unique shapes, call our team at Clearwater Exteriors and request a free quote. Our installers are experienced with procuring accurate measurements of all types of windows. After providing the measurements, we can even suggest quality replacement double-pane windows that will improve the energy efficiency of your property. 

Measure Replacement Window Height

Measuring the height sounds easy, but it is more in-depth than it seems. Height measurements must be taken in three places. Each measurement needs to be taken from the top board to the sill at the bottom — one measurement at the right, one at the left, and one directly down the middle. 

Here’s where it gets confusing. The sill is not the board that extends into your room. That board is officially called the “stool” (click for diagram). Therefore, if you are like most laypeople and don’t know the difference between the sill and the stool, we don’t recommend taking replacement window measurements on your own. Instead, call our trained team at Clearwater Exteriors to schedule replacement windows measurements and request a free quote. 

Measure Replacement Window Width

Like with the height, you need to measure the width in three places. Measure across from jamb to jamb. Again, this can be confusing because the jamb is not the same as the sash (outer frame). If you are unfamiliar with the differences, we suggest calling our replacement window company for assistance. 

Round the Numbers

Round your replacement windows measurements down to the nearest eighth of an inch. Replacement windows are sold in eighths of inches, so that is how your final measurements need to be stated. 

Contact Clearwater Exteriors for Professional Results

While you can measure replacement windows on your own, if you want to ensure the numbers are correct, contact our team at Clearwater Exteriors and request a free quote. Our installers have taken measurements for replacement windows at thousands of Denver, CO, area properties and are quick and efficient. Call our office today or reach out to our team online using this website.