How to get the proper measurement for replacement windows accurately

When asking for quotations from contractors, it is important to give the proper measurement for replacement windows. This is so that they can give you the exact price of how much it will cost and you can properly match one contractor’s quotation against another contractor’s one. All you need is a measuring tape and knowledge of where to measure from and you would be ready to ask for a quotation. Do note that this is only for regular rectangular shaped windows and not those with an arch. Those are much harder to measure, with the need to measure the diameter and radius as well.

For the width (breadth) of rectangular shaped windows, take note of the sliding pocket that the window goes into. That needs to be measured as well. Thus, place your measuring tape inside the pocket and measure all the way to the other end. For accurate proper measurement for replacement windows, make sure the measuring tape is perpendicular to the window frame so you are taking purely the width and not diagonally. Repeat this step at least two times in the middle and the top/bottom. You should get the same width throughout and that would be the proper measurement. If it differs, repeat the steps again. If they are still not the same, use the smallest measurement when asking for quotation. Measure as accurately as your measuring tape would allow you to.

For proper measurement for replacement window’s height, do not measure the sill. In other words, just take measurement of the height within the head and the sill. If the sill is slanted to facilitate flowing of rainwater out, measure the shortest distance, i.e. the highest part of the slanted sill. After that, repeat as usual to ensure that the height is uniform. Once again, if it differs, take the shortest readings.

The above measurements are the exact size that fits perfectly. However, during installation, the window has to be slightly smaller to be able to fit inside nicely. As such, proper measurement for replacement window is actually 1/4" less for the width, and 3/16" less for the height. In other words, if your measurement comes up to 46-2/4" X 54-8/16" (expressed as width X height), then the correct one you should give is 46-1/4" X 54-5/16. Honestly, my advice is if you can get a contractor to do the measurements, it will certainly be the best way out.