How to Measure for Blinds & Shades
Choose your mount. Measure your window. Calculate the finished size to order.
For blinds & shades, including cellular, roller, zebra and other blind styles. Not for curtains or drapery.
Window Measurements ≠ Order Size.
Window Measurements are the dimensions you measure. Your Order Size is the finished product width and height you enter when ordering: Order Width and Order Height. Measure first, then calculate your Order Size.
You’ll need: a steel tape measure, a pencil and paper. Measure each window separately and label your readings.
STEP 1
Choose your mount
Inside mount
Fits within the window frame for a built-in look.
Required for all no-drill products. These use tension mounting, not adhesive.
Outside mount
Fits outside the opening, over the wall or trim.
For compatible drilling options only. No-drill products cannot be outside-mounted.
Check the recess depth
For an inside mount, measure the usable depth from front to back. Check your product’s Required Window Depth or Minimum Depth for Inside Mount, and allow room for handles and moving parts.
Use the product’s exact requirement, not a universal depth rule.
Window compatibility & shallow recesses
Sliding and outward-opening windows usually support either mount. For inward-opening windows, an outside mount is generally recommended. Always check the product and window clearances.
About 2 1/2" is a general depth reference for many inside-mount products, not a universal minimum or a guarantee of a flush fit. With a shallow recess, the headrail may project beyond the frame or the product may not fit.
Choose an outside mount only if your product supports it. Do not convert a no-drill product to an outside mount.
STEP 2
Measure your window
Inside mount
Confirm the required recess depth, then measure within the opening.
All inside mounts: use the TOP inside width.
For cellular, roller, zebra and other blinds & shades, with either no-drill or drilling installation, measure across the top of the opening. Record this as your Window Width.
Also check the middle and bottom. If either is narrower than the top, contact us before ordering.
Measure across the top
The top reading is your Window Width. Here, it is 22 1/8".
Use this measurement to calculate your Order Width in Step 3.
Left, center & right
Measure from the top inside edge to the sill at the left, center and right. The longest reading is your Window Height.
Example shown: 30 1/8".
Measuring for an outside mount
Compatible drilling products only, not no-drill. Include any trim you want to cover. Add extra coverage in Step 3, not at this measuring stage.
Use the longest width
Drilled cellular shades and other blinds: measure the top, middle and bottom, including trim. Use the longest reading: 22 1/8" in this example, unless the product specifies otherwise.
Drilled roller and zebra shades: use the top width, 22" in this example. No-drill products do not support outside mounting.
Use the longest height
Measure the left, center and right, including trim. Use the longest reading.
Example shown: 30 1/8".
Diagrams are illustrative, not to scale.
STEP 3
Calculate your Order Size
Product-specific sizing instructions come first.
The adjustments below are general recommendations. Check your product’s sizing instructions for its exact deduction or coverage requirements. If these are unclear, contact us before ordering.
First, round UP to the next 1/8"
Use the Window Width and Window Height selected in Step 2. If a measurement is already an exact 1/8" increment, keep it unchanged. Otherwise, round up: 22 3/16" → 22 1/4". Use these rounded values as Window Width and Window Height in the formulas below.
Inside mount
Leave clearance for the product to fit.
Width: 22 3/16" → round to 22 1/4" → subtract 1/4" → order 22".
Height: 33 5/16" → round to 33 3/8" → order 33 3/8".
Outside mount
Add overlap for coverage and light control.
Width: 22 3/16" → round to 22 1/4" → add 4" → order 26 1/4".
Height: 33 5/16" → round to 33 3/8" → add 4" → order 37 3/8".
Add 4" in total to each dimension, not to every side. Follow product-specific minimums and check the available mounting space.
These calculation examples are separate from the windows shown in the diagrams.
Enter the finished dimensions once. Do not repeat the deduction or addition. The Order Width and Order Height you enter are the finished dimensions we manufacture.
Before you order
- Confirm the mounting option, recess depth and size limits for your chosen product.
- Measure and label every window separately.
- For every inside mount, use the top inside width. For outside mounts, follow the width rules in Step 2.
- Convert Window Measurements into your Order Size, applying rounding and size adjustments only once.
- Double-check your Order Width and Order Height before confirming the order.
Extra-wide window?
Two separate shades may be easier to operate and help reduce long-headrail bowing, subject to product limits and installation requirements.
Do not simply divide the opening in half. Email us the overall dimensions, a window photo and your preferred product so the sizing and mounting arrangement can be checked.
What if my finished product doesn’t match my order?
Eligible errors on our part may be covered by our 90-Day Free Redo Policy, subject to its conditions. It does not cover customer-confirmed measurement or configuration errors. Contact us if you need help before confirming your sizes.
Not sure? Ask before ordering.
Send your measurements, a clear window photo and the product you’re considering.