How to Measure Skylights and Arched Windows

Before you measure your arched window, decide whether you need an inside mount or an outside mount. An inside mount means you want your arch shade to fit inside of your skylight or arch window. Measuring for outside mount arches is the same as measuring for inside mount arches. The factory will make the necessary adjustments. However, with cellular shades, you will need to add 2 inches to the width and height of your initial measurements.

For both inside and outside mounts, measuring arches is simple.

• First, measure the base width inside the arch opening.
• Then measure the height at the middle, or tallest point inside of the arch opening.
• A perfect arch means that the height of the arch will be exactly half the width of the base measurement.

Tip: If it turns out that your window is not a perfect arch, you may need to consult professionals to help you and discuss your options.

Measuring for skylights is a similar process to measuring for arched windows. Make more than one set of measurements to ensure accuracy.

If you measure for an inside mount:

• While most other inside mounted products requires you to round down, you should round skylight measurements for inside mounts up to the nearest 1/8 inch. Deductions will be taken from your product that will allow for the rail seal, the foam tape that will be on the outside of the rails.
• Your skylight will need at least 2 inches of mounting depth inside the window for your product to be fully recessed. We highly recommend that you do not use a non-flush mount. However, if there's no other alternative, it is acceptable for your shade to stick out up to ½ inch from the window. Please account for anything in the window frame that might interfere with how the shade operates.
• On your order, please include the angle of the window, in addition to its measurements.

If you measure for an outside mount:

• With skylight shades, the procedures for outside mounts are the same as for standard rectangular shades.
• Make your measurements in three separate places in your window for both width and height. For a skylight window that is longer than 96 inches, be sure to make a measurement every 48 inches. Outside mounts require only a 1/2-inch flat surface for bracket attachment.

After you’ve recorded your measurements, create a measuring template for your window.

• Attach butcher paper or wrapping paper to the window, allowing space for lots of overlap. Make sure the paper has no folds, as this can cause inaccuracy.
• Trace the inside of the window frame and create an exact outline of the window with a pen or marker.
• Remove the paper from the window.
• Write the measurements of the shade down on the piece of paper. Make sure the dimensions match your actual window. You can test this by cutting out the drawing and placing it back against the window.
• Please label the template clearly. Include your name, and label the "Top" and "Room Side" of the window appropriately. Roll, not fold, the template and insert it into a mailing tube with your order.

Tip: Test your template by cutting out the drawing and placing it back against the window. If they line up, it’s accurate.