Measuring Guide
Measure once. Fit perfectly.
Getting accurate measurements is simple. Follow our step-by-step guide below — and remember, we'll verify everything in person before your blinds are made.
What you'll need.
Metal tape measure
Steel is best — fabric tapes can stretch and give inaccurate readings.
Pen & paper
Write down each measurement as you go. Label which window is which.
Phone or camera
Take a photo of each window so you can reference it when ordering.
First, choose your mount type.
How you want your blinds to hang determines how you measure. Both options look beautiful — it comes down to your window and personal preference.
Inside Mount
The blind sits inside your window frame for a clean, built-in look. This is the most popular option and leaves any attractive trim or woodwork exposed.
✓ Clean, built-in appearance
✓ Leaves window trim exposed
✓ Requires minimum ¾" depth
Outside Mount
The blind mounts on the wall or frame outside the window opening. Great for maximizing light coverage, making windows look larger, or covering shallow frames.
✓ Taller, more dramatic appearance
✓ No minimum depth requirement
✓ Better light blockage
Inside Mount
How to measure for inside mount.
Measure the width
Using your metal tape measure, measure the inside width of the window opening at the top.
Measure to the nearest ⅛ of an inch.
This is your ordering width. Don't make any deductions — our factory will make the necessary adjustments (approximately ⅛") to ensure a perfect fit.
Measure the height
Measure the height of the window opening at three points: the left side, center, and right side.
Record the largest of the three measurements.
This is your ordering height. Again — no deductions needed.
Good to know
Inside mount requires a minimum window frame depth of ¾". For a flush look (where the blind sits entirely inside the frame), you'll need at least 2¼" of depth. If your frame is shallower, consider outside mount instead.
Watch: How to measure for inside mount
Outside Mount
How to measure for outside mount.
Measure the width
Measure the total width of the area you want to cover.
We recommend adding 3–4 inches to the window opening width (1½"–2" overlap on each side) to minimize light seepage around the edges.
This total is your ordering width — it will be the overall measurement from bracket to bracket.
Measure the height
Measure the total height of the area you want to cover.
If you want the blind to extend above the window opening, add that extra height now.
This is your ordering height.
Good to know
Outside mount has no minimum depth requirement, making it perfect for shallow window frames, french doors, or situations where you want maximum light coverage. The blind fabric will be approximately 1¼" narrower than your ordering width to allow for brackets.
Watch: How to measure for outside mount
Tips for accurate measurements.
01
Use a metal tape measure
Fabric and plastic tape measures can stretch. A steel tape gives you the most accurate reading.
02
Measure each window individually
Even windows that look identical can vary by ¼" or more. Never assume two openings are the same size.
03
Record to the nearest ⅛"
Precision matters. Round down for inside mount width (use the narrowest reading) and use the tallest for height.
04
Don't make deductions
Give us the exact measurements you take. Our factory will apply the necessary adjustments for a perfect fit.
05
Check for obstructions
Look for handles, locks, or anything that could interfere with the blind's operation once installed.
06
We'll verify everything
Every Casa Lume order includes a free in-home verification visit. We confirm every measurement before manufacturing.
Measuring multiple windows?
If you're ordering blinds for several rooms, we recommend creating a simple sketch of each room with the windows labeled (e.g., “Living Room — Left,” “Living Room — Right”). Write your width and height measurements next to each window.
This makes the ordering process faster and helps our verification specialist confirm everything during your free in-home visit.
Still not sure?
We verify every measurement before your blinds are made.
Don't stress about getting it perfect. Every order includes a free in-home verification visit — we'll confirm everything fits before manufacturing begins.