Workbook: How To Measure Windows for Blinds

Now that the walls at the Florida condo are white, we’re faced with the pricey proposition of ordering shades for the windows. The former owner had installed sheer fabric honeycomb window blinds. While they’re quite practical, they’re not our style. And, since we’ve painted, they look horrendous. The walls are bright white, but the blinds are the color of cigarette smoke stained shades that one might find in a train station from the 1950s. That bad.


I didn’t think to take a photo that highlights just how bad the window treatments look now, but here’s what the living room looked like when we first got it. (Yes, the beadboard panelling was flesh toned.) I realize that the blinds don’t look like an atrocity here, but believe me, they do, especially with all the white walls and furniture. I must spend some time perusing shade sites for affordable blinds. I’m thinking Smith & Noble, The Shade Store, Blinds to Go, Blinds Express, and Blinds Chalet. Other ideas?


When we first moved in, we swapped out the metal Venetian blind (hard to believe people still have those) in the kitchen for a solar shade. What a difference. (The wallpaper with rows of nautical flags is gone now too.)

I wish I could show you brilliant “after” photos with sleek window treatments, but alas, we only have “before” pictures. However, we measured and recorded the dimensions for every window in the condo (thankfully, at his point my (handy!) husband knows how to measure for blinds.) I plan to place an order for as many as I can afford within our budget. (It will be holiday cash well spent.)

Here are detailed instructions for how to measure windows for blinds.


• Decide on whether you want to mount the shades inside the window frame, or outside. 

• Use a steel measuring tape for accuracy. 

• Measure all windows, even those which appear to be the same size, especially in older homes.

I N S I D E   M O U N T 


• An inside mount is a cleaner, sleeker look. Outside mounted shades are affixed to the window frame or above or beyond the molding, so the window frame is covered when blind is closed.

• Inside mounted shades can have at least a half-inch gap on either side due to the brackets. A lot of light can stream through so if you want complete darkness, best to opt for an outside mount.

• If you want an inside mount, check not just the minimum depth required for it to be securely fastened, but the minimum depth required for a flush mount so the roller does not stick out beyond the window frame.

• To measure the width for an inside mount, measure the distance across from the inside of the window frame at the top, middle, and bottom of the window. Round down to the nearest 1/8-inch. Use the smallest of the three measurements.

• Then measure the height on the left, middle, and right. Round each measurement down to the nearest 1/8″. For blinds, use the longest measurement; for roller shades use the shortest measurement.

O U T S I D E   M O U N T how-to-measure-outside-mount

• For an outside mount, measure the width of the area you want the shade to cover. This is normally about  2-inches beyond the window frame, to prevent light from shining through. Some companies subtract from your measurement to accommodate the brackets, so be sure to account for that if need be.

• Measure the height from top to bottom from the top inside edge to the window sill. Round up to the nearest 1/8-inch. Add at least three-inches to the height for optimum light control. If you want the shade to cover a larger area, account for that too.

• Be sure to read the instructions for how-to measure for blinds for the specific brand you are purchasing; each company has its own quirks and guidelines. Shades can be expensive and they’re not returnable, so record your numbers carefully and double check your work. Or, you could always hire a professional.

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Author: StyleCarrot

Marni Elyse Katz is a design writer and editor who lives in Boston and Cape Cod with her husband, two sons, and a cat. She blogs about design at

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