How to Measure for Arch Window Coverings

Tips Before You Get Started

  • Arch window coverings include cellular shades, pleated shades and composite wood shutters 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 ⅛", making sure to clearly identify which is your height and which is your width—it is very common to get them mixed up

Perfect Arch

Perfect Arch
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

Perfect Quarter Arch
Perfect Quarter Arch
Non-Perfect Quarter Arch
Non-Perfect Quarter Arch
Elongated Quarter Arch
Elongated Quarter Arch

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

Palladian Arch
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

Eyebrown
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)

Elongated Arch
Palladian 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".