A motorized shade is made to order, so a wrong measurement means a shade that will not fit and a second lead time. Knowing how to measure for motorized shades comes down to four things: the mount type, three widths and three heights, the depth the motor and roller need, and where the power reaches the shade. This shade measurement guide covers each, plus the obstructions that catch installers out.
How do you measure for motorized shades?
Choose inside or outside mount first. For inside mount, measure the opening width at the top, middle and bottom and use the narrowest, measure height in three places, and check the depth the motor needs. For outside mount, measure the area to cover. Record exact figures and let the maker apply any deductions.
How to measure for motorized shades: before you start
Measuring well starts with the right tools and a plan for each window.
- A steel tape measure. Cloth tapes stretch. Read to the nearest 1/8 inch, or the precision the maker’s form asks for.
- A measurement sheet. One row per window: room, window number, mount type, every width and height, depth, obstructions and motor side.
- The maker’s measuring guide. Depth minimums, clearances and deductions vary by product line, and the guide for the exact shade governs.
Measure every window, even ones that look identical. Openings in the same house can differ by more than the tolerance a shade allows.
The Building America Solution Center, run by Pacific Northwest National Laboratory for the U.S. Department of Energy, advises that window attachments be installed per the manufacturer’s instructions, and its guide to window attachments recommends prewiring new homes for motorized shading. Both points shape how you measure.
Inside vs outside mount shades
An inside mount sits within the window opening; an outside mount fixes to the wall or trim above it and covers the opening. Decide this first, because each one is measured differently.
| Factor | Inside mount | Outside mount |
|---|---|---|
| What you measure | The opening itself | The area the shade should cover |
| Depth needed | Enough for the brackets, roller and motor | Flat mounting surface above the opening |
| Light gaps | Small gaps at each side | Fewer, with overlap past the opening |
| Obstructions | Cranks and handles can block the fabric | Shade clears most hardware |
| Look | Clean, shows the trim | Covers the trim, can make the window look larger |
An inside mount looks tidier, but only if the opening is deep and square enough. When it is not, an outside mount solves depth and obstruction problems at once.
Measuring an inside mount: width, height and depth
Inside mount measuring is where most ordering mistakes happen. Work in this order.
- Width at three points. Measure inside the opening at the top, middle and bottom, frame to frame. Record all three, and use the narrowest, so the shade fits at the tightest point.
- Height at three points. Measure from the top of the opening to the sill at the left, center and right. Record all three; the maker’s guide says which one to order. The PNNL guide suggests leaving an interior shade’s bottom rail 1/2 inch above the sill so air can move across the glass.
- Depth. Measure from the front edge of the opening back to the glass or the first obstruction. Compare it with the maker’s minimum for a partial recess and for a flush mount, and check whether a fascia or cassette adds depth.
- Square. Measure both diagonals. If they differ noticeably, an inside mount may show uneven gaps, and an outside mount may suit better.
A motor can change the depth a shade needs, because it sits inside the roller tube or at one end, and the figure can differ from the manual version of the same shade. The depth figure comes from the maker’s guide for that motor and fabric, never from a general rule.
Measuring an outside mount
For an outside mount you decide the size of the shade, then confirm there is somewhere solid to fix it.
- Width. Measure the opening, or the outside of the trim, and add overlap on each side to reduce light gaps.
- Height. Measure from where the brackets will sit down to where the shade should stop, usually the sill or below it.
- Mounting surface. Check for a flat surface above the opening, tall enough for the brackets the maker specifies, with framing or anchors to hold the weight.
Worked example: on a 36 inch opening, if you choose 2 inches of overlap on each side, the shade width is 36 + 2 + 2 = 40 inches. Write down the finished size you want, and state on the order that it is an outside mount.
Check for obstructions: handles, cranks and sensors
Hardware in or around the opening decides whether an inside mount works at all. Walk every window and note:
- Casement cranks and handles. These often stick into the opening and stop the fabric or bottom rail. Measure how far they protrude, or plan an outside mount.
- Locks and tilt latches. Note where they sit relative to the shade’s path.
- Window contacts and sensors. Alarm contacts and glass break sensors near the frame must stay clear; see our guide to glass break sensor placement.
- Trim, tile returns and sloped sills. These change the usable depth or height at one point only, which is why you measure in three places.
Motor side and power location
A motorized shade adds two measuring items a manual shade does not have: which end the motor sits at, and where its power arrives.
- Motor side. Record left or right as seen from inside the room. Keep it consistent across a room so cables and access line up.
- Wired motors. Measure where the cable exits relative to the opening: the distance from the corner and whether it comes from the head, the side or the ceiling. It must land at the motor end, hidden by the bracket or fascia.
- Battery motors. Note whether a battery wand or solar panel needs room beside or on top of the shade.
Choosing between a hardwired and a battery motor, and what to run at rough-in, is covered in our guide to wired vs battery motorized shades. If the shades will join a hub by radio, our Z-Wave vs Zigbee comparison covers protocol choice.
Recording and ordering without deductions
Give the maker exact measurements and let it apply the deductions. Never deduct for clearance yourself unless the maker’s guide tells you to; if it already deducts for an inside mount, your own deduction makes the shade too narrow twice over.
- State the mount type clearly for every window.
- List width before height, in the order the maker’s form uses.
- Note the motor side, power location and any obstruction.
- Recheck any window where the three widths or heights differ widely.
The Bursma motorized shades category lists the LUTRD-PB-WH insulating honeycomb shade and wall keypads such as the LUTRRD-W6BRL-WH 6-button keypad with raise and lower, part of the security and home automation division. For pricing and availability, ask your sales representative through the Bursma contact page, or apply for a Bursma dealer account.
Frequently asked questions
Which width do I use for an inside mount shade?
Use the narrowest of the three widths measured at the top, middle and bottom of the opening. Give it to the maker exactly and let the maker apply its own clearance deduction.
Should I deduct from my measurements?
No, unless the maker’s measuring guide says to. Many makers deduct for inside mounts themselves, so a second deduction leaves the shade too narrow.
How much depth does a motorized shade need?
It depends on the product, the motor and whether a fascia or cassette is fitted. Check the maker’s guide for the minimum depth for a partial recess and for a flush mount.
When should I choose an outside mount?
When the opening is too shallow, out of square, or blocked by cranks or handles, or when you want the shade to cover the trim and reduce light gaps.