Looking for the perfect fit for new window treatments? It all starts with an accurate measurement. Most hardware packages come with everything you need for installation in wood or drywall. For metal or masonry, make sure you have the right drill bits and the appropriate screws for installing window treatments.

Before taking any measurements, determine if the window treatment will be installed as an inside mount or an outside mount. Use a metal tape measure to measure accurately to the nearest 1/8-inch. Do not round down.

Inside Mount

Inside mount treatments are installed inside the window casing. They are frequently used in conjunction with draperies, which mount outside the window. Inside mounts can also offer a clean, streamlined look. They don't provide as much light control as outside mounts.

How to Measure (Inside Mount)

• Measure inside the window frame in three places for width: top, middle, and bottom. Record the narrowest width.
• Measure height on the left, middle, and right. Record the longest height.
• Measure the depth of the window to determine if blinds will fit.

Additional Considerations:

• Don’t round down. The factory will adjust sizing for perfect fit.
• Confirm the mounting depth requirements for your selected product.
• Measure in multiple places both vertically and horizontally.

Outside Mount

Outside mount window treatments are mounted outside the window casing. They are a popular choice when blinds are the only window covering. Extending them past the window provides maximum light control.

How to Measure (Outside Mount)

• Measure the full area you want to cover: width and height.
• Add at least 3 inches to both measurements for better light control & privacy.
• Extra space allows for headrails and mounting brackets (up to 2.5" tall).

Additional Considerations:

• Allow extra space for headrails and brackets.
• Account for obstructions such as doorknobs, deadbolts, or molding.
• Outside mounts need at least 2 inches of flat surface above the window.

General Measuring Tips

• Decide between inside or outside mount before measuring (or measure both ways if unsure).
• Use a metal measuring tape for accuracy.
• Measure to the nearest 1/8-inch.
• Always record width first, height second (W × H).
• Double check numbers to avoid transposing measurements.