How To Measure Blinds for Arched Windows

Everything you need to correctly measure for arched window blinds and shades

Getting Started

Tips before you get started:

Use a steel tape measure for the most accurate measurements
If you’re considering an Inside Mount, make sure your window has enough depth to accommodate it
Always measure width (left to right) first and height (top to bottom) second
Record all measurements to the closest 1/8”, making sure to clearly identify which is your height and which is your width—it is very common to get them mixed up

Tools you will need:

Steel Measure Tape
Step Ladder
Pencil/Paper

Perfect Arch

In a perfect arch the height is exactly half the width. If not exact, it's a non-perfect arch. For non-perfect arches you'll likely need to provide a paper template of your window. Please call us at 800-575-8016 for more information.

Width: Measure from left to right at the bottom of the arch. If you plan to mount a window covering below the arch (arches often sit above another window), consider where each window covering will need to be mounted.
Height: Measure from the center of the width to the highest point on the arch.
For an inside mount, order your product in the exact measurements you took, making no deductions. The factory will apply deductions when making your product.
For an outside mount, add 2" to both the width and height to get your final measurements. Your product will be made in the exact sizes you provide.

Quarter Arch

diagrams of perfect, non-perfect, and elongated quarter arches

A quarter arch is one half of a regular arch. It consists of a right angle with the arched section diagonally across from the angle. To be a perfect quarter arch, the width at the bottom of the arch must be exactly the same measurement as the height. For non-perfect and elongated quarter arches, you'll likely need to provide a paper template of your window. Please call us at 800-575-8016 for more information.

Width: Measure from left to right at the bottom of the arch. If you plan to mount a window covering below the arch (arches often sit above another window), consider where each window covering will need to be mounted.
Height: Measure the straight side, from the base of the arch to the tallest point.
For an inside mount, order your product in the exact measurements you took, making no deductions. The factory will apply deductions when making your product.
For an outside mount, add 2" to both the width and height to get your final measurements. Your product will be made to the exact sizes you provide.
Make sure you have a good mounting surface on both the bottom and the side, since this arch style may require mounting on both sides.

IMPORTANT: If you wish to order an arch window covering online, it must be a perfect arch or perfect quarter arch (as defined above). For all other arch styles, please call us at 800-575-8016 to discuss your options with one of our Design Consultants.

Palladian Arch

In a Palladian arch, the height is more than half the width. The arched part is steeper compared to the perfect arch.

Width: Measure from left to right at the bottom of the arch. If you plan to mount a window covering below the arch (arches often sit above another window), consider where each window covering will need to be mounted.
Height: Measure from the center of the width to the highest point on the arch.
For an inside mount, order your product in the exact measurements you took, making no deductions. The factory will apply deductions when making your product.
For an outside mount, add 2" to both the width and height to get your final measurements. Your product will be made in the exact sizes you specify.

Eyebrow Arch

Eyebrow arches are shorter in height than perfect arches.

Width: Measure from left to right at the bottom of the arch. If you plan to mount a window covering below the arch (arches often sit above another window), consider where each window covering will need to be mounted.
Height: Measure from the center of the width to the highest point on the arch.
For an inside mount, order your product in the exact measurements you took, making no deductions. The factory will apply deductions when making your product.
For an outside mount, add 2" to both the width and height to get your final measurements. Your product will be made in the exact sizes you specify.

Eyebrow Arch with Legs (Also Known as an Elongated Arch)

This style has two vertical sides, often called "legs", leading up to where the arch starts. There are four different measurements required for this style.

Width: Measure from left to right at the bottom of the arch. If you plan to mount a window covering below the arch (including the "legged" portion), consider where each window covering will need to be mounted.
Height: Measure from the center of the width to the tallest point of the arch.
Measure each leg's height, from the base to the point where it starts to curve into an arch. Always measure both, since the legs could have slightly different measurements.
For an inside mount, order your product in the exact measurements you took, making no deductions. The factory will apply deductions when making your product.
For an outside mount, add 2" to both the width and height to get your final measurements. Your product will be made in the exact sizes you specify.

Important Notes

Make sure you have a good mounting surface at the base of the arch as most arches are bottom mount only.
The minimum window opening depth for inside mount is 1 ½". If you want your window covering fully recessed (not sticking out of the window opening at all), the minimum depth is 2 ¼".
Round down to the nearest ⅛" if your measurement falls on a 16th or 32nd mark.
For cellular (honeycomb) shades and pleated shades: You can get side mounts upon request only. They are not available for arches wider than 40".