How Do You Measure For Replacement Windows?

If you’ve searched far and wide to find the right window replacement for a prominent room in your home, you don’t want to risk bringing home a brand new window in the wrong size. Saving time before you buy is the key to creating a low-stress situation, especially if you’re a new homeowner who’s not totally clear on how to replace old windows. However, there’s no need to worry. Measuring your window is easy if you know the right way to do it. Whether you’re refitting your window due to damage or are looking for ways to cut down on energy bills by purchasing brand new, energy-efficient windows, measuring for a new window doesn’t have to be difficult. With the right tools and know how you’ll be able to order the perfect size in a snap. If you’re not sure about how to measure your home for new windows, here is a simple guide.


Many homeowners get tripped up due to the extra space around their window. Where should the measurement start? At the frame? Inside the jamb lining? The answer is simple. You want to make sure you’re measuring the size of your window and nothing else. Not the frame, not the interior lining. Your windows are held together by head and side stops, as well as a jamb, which can be found at each corner, and jamb lining, which provides extra support around your window. To get a true measurement, avoid your jambs, starting with your measuring tape placed exactly where the jambs and lining end. Your window’s width is a side-to-side measurement. To get an accurate measurement, you’ll need to measure in three places. Starting at the top, work your way down to the middle and bottom of the windows, using your jamb ending points as markers. The smallest value of all these measurements will be the official number you use.


Getting the correct depth measurement for your window can be tricky, especially if it’s still installed in the frame. Your window’s depth is the space between the interior window frame and the exterior, minus the window’s framing. To get a correct measurement, start inside your frame and measure the top, middle, and bottom area once more, using the smaller measurement as your true measurement. However, keep in mind that you’ll need to have at least a 3 1/4 inch space between your trim and outer strip in order to get the right depth for installation.


Finally, you’ll need to measure your window’s height. Moving from left to right, measure your window’s height in three parts and use your smallest number for your final measurement. Again, start from the beginning of the actual window, not the start of the glass pane or the head stopper or jamb, in order to get the most accurate measurement. Using a measurement that’s even slightly off could create unwanted drafts and leaks in your home, creating a hazard for your health and safety in the long run. If you’re not sure about your measurements, ask a professional to weigh in, or ask the company you’re ordering new windows from what stock sizes their windows come in. Many homes come with windows of a conventional size that can be swapped out with most newer brands. However, if you’re in an older home, you might be dealing with an irregular-sized window, in which case you’ll need to search for a customized option.

Don’t Measure Extra Features

Replacement windows are mostly made to be easy to install and quickly transferable from home to home, especially when it comes to sash windows like double-hung windows and other common styles. However, getting the measurements right is crucial to ensure that you get the snuggest fit for your home. Getting a window that’s slightly too small could be mean trouble, and getting a window that’s even slightly too big could cause problems in hotter weather when wood starts to retain moisture and swell. If you want to protect your windows and your home from damage, don’t take chances by ordering the wrong window size. Remember to ignore the sash, trim, and jamb lining when measuring your window to get the most accurate possible number. For best results, have a helper stand by to hold down the measuring tape taut at the window sill to help you get a perfect measurement. If you run into any doubt or if you have questions about your window installation, don’t hesitate to ask your window company before you reorder.

Author: WebEditor

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