How to Measure Blinds & Shades

Window Measuring Overview

Inside Mount or Outside Mount?

• Inside (IB) Mount – Shade fits within window frame.
• Outside (OB) Mount – Shade overlaps window opening.

Be sure to add the desired overlap amount to each side and then add to the total ordered width when ordering an outside mount shade.

• End (EB) Mount – Shade is mounted at the top left and right side corners.

Standard Measuring Procedures

Inside (IB) Mount 

1. Be sure the window opening is deep enough to install the mounting bracket. Refer to the Mounting Charts for recessed mounting depths for each product.
2. Measure the width inside the window opening at the top, middle and bottom. The top measurement is critical because the headrail must fit. The top measurement should always be the ordered width. Vertical applications require a top measurement only; middle and bottom measurements are not required.
3. Measure the height inside the window opening at the left, center and right.
4. Measure the window on the diagonal. If the two diagonal dimensions are not exactly the same, it may be necessary to specify an outside mount for optimal light control and privacy.
5. The ordered width should ensure a precise fit for the headrail and allow proper operation of the shade. If widths in the window vary, order the minimum width necessary to allow the shade to go up and down.
6. The ordered height should ensure clean operation at the base of the window, as well as provide maximum privacy and light control. If heights in the window vary, order the shortest height for vertical treatments and the longest height for horizontal treatments – except Alustra® Silhouette®, Silhouette and Nantucket^TM shadings, where the shortest height should be ordered to allow for full rotation of the bottom rail.

Outside (OB) Mount

1. Measure the desired width and height. To minimize light leakage, the shade should overlap the window opening at least 2″ on each side and at the bottom. Refer to the Mounting Charts for recommended overlaps for each product.
2. When measuring the height, take into account the requirements for mounting the bracket attachment.

How to Measure for Unequal Panel Widths with Two- and Three-on-One Headrail

1. Measure the overall width. Use the narrowest measurement with inside mounts. With outside mounts, we recommend a 3″ overlap on all sides.
2. Without moving the tape, measure the location of the desired split (usually a vertical mullion).
3. Enter all measurements on the order form – overall width, left panel width, center panel width (if required), right panel width and height.
4. All panel widths combined must equal the overall width.
5. The smaller panel must be at least 1/3 the size of the larger panel (Alustra® Silhouette®, Silhouette and Nantucket^TM window shadings, and Alustra Vignette® and Vignette Modern Roman Shades only).

Stackback Measuring Procedures

Stackback should be considered for a window opening that is to be fully uncovered when the treatment is drawn open.

Outside (OB) mount treatments

1. Measure the desired uncovered width, rounding your measurement down to the nearest 1/8″. With side stack units, include the desired amount of overlap for the side opposite the fabric stack in this measurement. Refer to the individual product specifications for recommended overlaps, also taking into consideration trim or molding.
2. Using the stackback charts created for the product in each product section, locate the uncovered width (clear opening) measurement under split stack or side stack design.
3. Find the corresponding “stackback” for that range.
4. Add the stackback to the uncovered width to get the correct width to order.
5. After determining the correct width to order, confirm that there is enough room to outside mount the treatment on the opening at that width.

Cut Outs

A cut-out is a small rectangular area removed from a shade to avoid obstructions, usually from one of the corners or from the bottom. Not all products allow cut-outs. Refer to the specific product section to verify availability. When a cut-out is required, provide detailed measurements of the area to be removed. In addition, include your measurements on a sketch of the cut-out to ensure accurate communication of the order.

Corner Windows

Butt and Bypass Shades

When two shades butt against each other at a corner, as shown in the overhead views at right, one shade is the “butt” shade and the other is the “bypass” shade. Measure each shade separately using the procedures just described, and then subtract headrail depth from the butt shade to obtain the proper ordering width. With outside mounts,
remember to allow for overlap on the sides and at the bottom. Refer to the Mounting Charts for headrail depth for specific products.

Note: See the Design Studio^TM Roman Shades section for Corner Mount valance measuring instructions.

Corner Windows

When Not Using Butt and Bypass

Some products, such as Alustra® Luminette® and Luminette Privacy Sheers, cannot use butt and bypass. They are measured to simply meet in the corner.

1. Measure the width of both openings to the common corner.
2. Deduct the necessary depth of the treatment (deduct 3″ for Luminette Classic, or 4″ for Luminette Quintette®) from the width of each measurement so that they will meet in the corner but not overlap. Note: If spacer blocks or extension brackets will be used for extra clearance on outside mounts, add the amount of extra clearance to the deduction.
3. Order the width less the deduction for each window.  Refer to the Installation, Operation and Care instructions for detailed information and illustrations.

Bay Windows

With bay windows, location of the window treatment and the ordered width are marked and measured as illustrated below.

1. Determine the depth of the product you are mounting (use 3″ for Luminette Classic, and 4″ for Luminette Quintette) and use this for the width of your poster board.
2. Cut two pieces of poster board [depth determined from #1 above] wide by 12″ long. Note: If spacer blocks or extension brackets will be used for extra clearance on outside mounts, add the amount of extra clearance to the width dimension of the poster board before measuring.
3. Place the strips in the left angle first and bring them together until the front corners of the poster board meet. Mark points A and B.
4. Repeat this step for the right side angle, marking points C and D.
5. Measure between points B and C to obtain the width measurement of the center window treatment.
6. Measure from point A outward to the desired width to obtain the width measurement of the left window treatment.
7. Measure from point D outward to the desired width to obtain the width measurement of the right window treatment.

Skylights

With inside (IB) mount Duette® and Applause® Simplicity^TM and Duette SkyLift^TM shades:

1. Measure the width and height inside the window opening in at least three locations each. If the window opening is longer than 96″, measure the width every 48″.
2. Order the narrowest width and the shortest height.
3. Round your inside mount measurements up to the nearest 1/8″, not down as with other inside mounts. 

Note: With Duette SkyLift honeycomb shades, factory deductions take into account the application of a light gap strip (rail seal) to the outside of the rails.

With outside (OB) mount Duette and Applause Simplicity shades: 

1. Measure the desired width and height. To minimize light leaks, the shade should overlap the window opening at least 2″ on each of the four sides.
2. When measuring the height, take into account the requirements for mounting the bracket attachment.  In addition to the shade measurements, the angle of the window should also be noted.

With outside (OB) mount Duette SkyLift shades:

1. Measure the desired width and height. To minimize light leaks, the shade should overlap the window opening at least 2″ on each side.
2. Along the width sides, there must be at least 1 3/4″ of flat surface for proper bracket attachment.