Measure from the inside left of the window opening to the inside right. Survey three places and record the narrowest dimension, then deduct ¼ – ½ inch for adequate margin when closing. Divide this calculation by two (2) for the individual exterior shutter width.

Start by measuring the width of the window. As a rule of thumb, each shutter will be half the width of your window. Once you have verified the width, measure the height of the window. Note: It is always a good idea to measure twice for accuracy. If the dimensions do not match, use the smaller of the two values.

First, measure the width of your window. The width is typically the width of the window opening. Once you have the width measured, divide by 2 and this is your shutter width for each shutter. Next, measure the height of the window opening. Measure on each side of the window, especially older windows.

Tips for Measuring for External Shutters For short single windows that are shorter than they are wide, divide the width by 4 instead of by 2. When measuring double windows, divide by 4 instead of 2. If this is similar to the width of shutters needed for single windows, use the single window measurement. Divide by 6 for triple windows