How to Measure and Install Blinds

• Horizontal blinds have tilted slats to control sunlight.
• Vertical blinds are popular for sliding glass doors and large windows.
• Energy-efficient blinds keep cool air in during the summer and cold air out during the winter.
• Blackout shades block nearly 99% of sunlight from entering a room.
• Some blinds have remote controls to easily adjust for more or less light.

Ways to Install Window Blinds

• Install inside-mounted blinds within the window.
• Install blinds with outside mounts to cover the window frame or attach to the wall.
• If the window frame is sufficiently deep to attach the mounting brackets inside the window frame, you can choose inside or outside mounting. If not, you’ll have to use an outside mount.
• Outside mounts require a sturdy wall surface or trim for attachment, making it the ideal installation method for standard doors. Inside-mounted vertical blinds won't work on standard doors.
• Refer to your window blind packaging and instructions for specific measurements or requirements for the blinds you choose.

Vertical blinds work best for a window that's wider than its height or for sliding doors. They can be installed either inside-mounted or outside-mounted. Inside-mounted vertical blinds won't work on doors. Use an outside-mount installation.

Instructions
Step 1: Measure the Width
Measure the width inside the window frame at the top, middle and bottom and round down to the nearest 1/8-inch measurement. Use the smallest measurement as the window width so the blinds clear the sides of the window frame.

Step 2: Measure the Height
Measure the height inside the window frame from the top of the opening to the sill at the left, middle and right. Round down to the nearest 1/8-inch measurement. Use the smallest measurement as the window width so the blinds fit within the opening.

Step 3: Select Your Inside-Mounted Vertical Blinds
Take these measurements to Lowe’s to select your inside-mounted vertical blinds.

Here's how to measure for outside-mounted vertical blinds.

Instructions
Step 1: Measure the Width
Measure the width of the window or door. For maximum light control, add 4 inches to each side for a total of 8 inches added to the entire width.

Step 2: Mark the Location of the Blinds
Mark the location where you’ll install the window blind headrail. Most manufacturers recommend installation at least 3 inches above the window or door opening.

Step 3: Measure the Height
Measure the height from the headrail location to the sill at the left, middle and right sides of the frame. Use the smallest measurement.

Step 4: Allow for Operating Clearance if Necessary
If the blinds will hang to the floor, deduct 1/2 inch from the height to allow for operating clearance.

Step 5: Select Your Outside-Mounted Vertical Blinds
Take these measurements to Lowe’s to select your outside-mounted vertical blinds.

Here’s how to measure for blinds for patio doors.

Instructions
Step 1: Measure the Width
Measure the width inside the window frame at the top, middle and bottom and round down to the nearest 1/8-inch measurement. Use the smallest measurement as the window width so the blinds clear the sides of the window frame.

Step 2: Measure the Height
Measure the height from where the top of the blinds will be located to the floor on the left side, middle and right side of the glass section of the door. The blinds should overlap the top of the glass by at least 3 inches.

Step 3: Deduct for Operating Clearance
Deduct a 1/2 inch from the height to allow for operating clearance.

Here’s how to measure for vertical blinds for French doors.

Instructions
Step 1: Measure the Width
Measure the width of the glass and add a minimum of 1 to 2 inches to both sides of the glass. Note that the door handle may constrain the maximum amount that the blinds can overlap the glass on either side.

Step 2: Measure the Height
Measure a minimum of 2 inches above and below the glass on the door. Note that measuring 3 inches above the glass is recommended. This will provide enough room to mount installation brackets at the top and hold-down brackets at the bottom. The extra height above your window will also allow the blinds to stack up above the glass and provide an unobstructed view.

Here’s how to measure for outside-mounted windows with moulding or trim.

Instructions
Step 1: Measure the Width
Measure from the far-left edge of the trim to the far-right edge of the trim. For wood blinds, faux wood blinds, aluminum blinds and other products with mounting brackets at each end, deduct 1/4 inch from the measurement to allow room to mount the end brackets onto the trim.

Step 2: Measure the Height
Measure the height from the top edge of the window trim to the bottom edge of the window trim or the sill. To mount the blinds above the window trim, start your measurement at least 2 inches above the top edge of the trim and measure down to the bottom edge of the window trim or sill.

Flush
An inside-mounted valance is manufactured with straight-cut edges on both ends. This type of valance looks best when mounted flush to the window casing. The width of the valance is determined by the width of the window treatment — drapes, shades, shutters, etc. Measure the depth from the innermost part of the window, where the bracket will be mounted, to the outermost part of the window casing to make sure the window is deep enough for a full-recess flush mount.

Partial Recess
Partial-recess valances always have returns, or side pieces. The corners are mitered, and you should select a return length to cover the difference between the flush mount requirement and the window’s depth. Depending how far the valance extends beyond the window casing, you can order returns to cover the ends of the headrail and valance.

Outside Mount
An outside-mounted valance is manufactured with standard returns sized to cover the ends of the headrail and valance for a finished look. Measure the width of the area the valance will cover. Add additional space for window treatments and mounting hardware. Also measure the distance the valance will extend from the mounting surface.