How to Measure for a Replacement Window

If your windows are in need of repair, you will need to know the measurements of the existing windows in order to place an order for the new windows that you need. You will need to be sure that your measurements are accurate so that your new windows are the right size for your home.

1. Inspect your existing windows to determine the type of windows that you are currently using. Most windows come pre-installed with a window frame attach. This window casing is part of the window assembly and is factored into the measurements of your window.


2. Measure the window from the outside of the window frame from right to left to determine the width of the rough opening of your window.


3. Measure the window frame from top to bottom in order to determine the length inches of the length of the window that you are replacing.


4. Measure twice, just in case of an error the first time. Often new windows will have to be ordered if they are a specialty size and are not correct in the store. For this reason it is very important that you measure accurately so that the windows that you purchase are going to fit perfectly into the rough opening of the window on your home.


5. If you are in doubt on the size of your windows, you may want to deduct 1/2 inch from your measurements just in case. If the window is 1/2 inch too small, this can easily be filled in with shims. However, if the window is too large and will not fit into the rough opening, you will have to return it and reorder new windows. It is better to have it a little too small than too big.