How to Measure and Choose Cut-to-Size Bamboo Blinds?

Measure the smallest width and the tallest height in three spots, then round width down and height up to the nearest 1/8 inch.

For the full breakdown, see our best Bamboo Blinds and Shades guide.

A window that looks square rarely is, and bamboo blinds ordered a quarter inch too wide will not drop into the frame no matter how hard you push. Cut-to-size bamboo blinds live or die on two decisions made before you spend a dollar: the mount type and the tape measure reading. Get both right and the blind slides in clean on the first try.

The measuring itself takes about ten minutes per window. The gate check comes first, though, because inside mounts only work when the frame has enough depth for the brackets.

Inside Or Outside Mount: Which Fits Your Window?

An inside mount sits within the window frame and needs enough depth clearance for the headrail and brackets; an outside mount hangs on the wall or trim above the opening and always works, but requires you to add overlap on every side. Measure the mounting depth before you decide.

For an inside mount, check the distance from the wall face to the front of the trim where brackets will install. If that depth is shallower than the headrail your shade needs, the blind will not sit flush and you are better off going outside mount.

Outside mounts trade a little wall space for full light control. The Bali wood blind measuring guide recommends adding at least 2 inches to each side for width and 2 inches at the top and bottom for height, with more overlap if you want extra coverage. For bamboo and woven wood shades specifically, a 1 1/2 inch overlap on each side is a common recommendation to close light gaps.

Whichever route you pick, the mount type changes every finished dimension. Decide it before the tape comes out.

How To Measure For Inside Mount Bamboo Blinds

Measure width at the top, middle, and bottom of the opening and use the smallest of the three; measure height at the left, center, and right and use the largest. That pairing gives you a blind that fits even when the frame is slightly out of square.

Work with a steel tape measure, not a cloth one. Fabric tapes stretch and sag, and on a 40 inch opening a stretched tape can cost you a quarter inch that shows up as a gap on one side.

Once you have the three width readings and the three height readings, apply the rounding guidance used by bamboo blind measuring guides:

• Width: round down to the nearest 1/8 inch.
• Height: round up to the nearest 1/8 inch.
• If a reading lands on a 1/16 or 1/32 inch increment, apply the same rule — down for width, up for height.

Record the numbers in inches with fractions, not decimals, because most blind order forms ask for inches and eighths. Write both the raw reading and the rounded figure next to each window so you can double-check the order later.

One more pass before ordering: hold the tape against the depth of the frame at the bracket location and confirm your chosen headrail will clear it. This is the single check that separates a blind that fits from one that gets returned.

Outside Mount Measurements And Sizing Choices

For an outside mount, measure the area you want covered, then add overlap rather than subtracting anything. Start with the width of the opening plus at least 2 inches on each side and the height plus at least 2 inches top and bottom.

The overlap is what kills light bleed along the edges. If the window sits close to a corner or a cabinet, you may not have room for the full 2 inches on that side, so measure the actual wall space available and let that limit the overlap instead.

Choosing material comes down to the room, not the measurements. Bamboo blinds suit covered porches, sunrooms, and rooms where you want filtered light and a warm texture. Woven wood shades in the same family work well indoors where you want the same look with more color range. If you want to compare specific styles before committing to a size, this roundup of tested bamboo blinds and shades covers the options worth measuring for.

Order forms for cut-to-size bamboo are unforgiving on one point: the finished width you type is the width you get, with no allowance added by the manufacturer. If you measured for inside mount, enter the smallest width exactly. If you measured for outside mount, enter the width after overlap has been added, not the raw opening.

Why Bamboo Blinds Get Ordered Wrong

Nearly every sizing failure traces back to one of four habits, and three of them are fixed by slowing down for a single extra minute per window.

• Measuring once instead of three times, which misses an out-of-square frame.
• Using a cloth tape, which stretches and reads long.
• Measuring the window before deciding mount type, so the overlap or inset never gets added.
• Skipping the depth check, which makes an inside mount physically incompatible.

The Bali measuring guide and the bamboo blind guides all point at the same discipline: three readings, steel tape, and a mount decision locked in first.