Steel tape measure
A metal tape, not cloth or plastic. Cloth tapes stretch and throw the size off.
How to measure your windows for blinds and shades
Measuring your own windows takes about two minutes each and gets you a faster, firmer quote. You need three things: a width, a height, and whether the shade mounts inside or outside the frame. Rounded sizes are fine to start — we confirm every measurement before we build.
Two minutes per window
What you'll need
A steel tape measure, a pencil, and somewhere to write. Always measure the width first, then the height, and write sizes as width × height. Measure to the nearest 1/8".
Width then height
Always in that order, written width × height. It's how every size on your quote is read.
Round to 1/8"
Round each measurement to the nearest eighth of an inch. Close is fine for a quote.
Start here
Step 1 — Choose your mount
Before you measure, decide where the shade sits. It changes which size you record. If you're not sure, outside mount is the safe choice — or tell us and we'll advise.
Inside mount
The shade sits inside the window frame for a clean, built-in look that leaves the trim showing. It needs a little depth in the frame to fit — most windows have enough. If your frame is shallow, go outside mount.
Outside mount
The shade mounts on the wall or trim above the opening and covers more than the glass. Best for blocking light around the edges, hiding an uneven frame, or making a window look larger. No depth needed.
Width first
Step 2 — Measure the width
Windows are rarely perfectly square, so measure the width in three places — top, middle, and bottom. Round each to the nearest 1/8".
- Inside mount: record the smallest of the three widths. The shade has to clear the narrowest point.
- Outside mount: measure the area you want to cover. If there’s room, add a couple of inches on each side for better light control and privacy.
Do not subtract anything. Give us the exact opening — we make the fit deductions ourselves (see Step 4).
Then height
Step 3 — Measure the height
Measure the height in three places — left, centre, and right. Round each to the nearest 1/8".
- Inside mount: record the largest of the three heights, so the shade covers the full opening.
- Outside mount: measure from where the shade will start, above the opening, down to where you want it to end — the sill, or a little below it.
Write the size as width × height. That’s everything we need to quote.
One rule: give us the exact opening
Don't round down or shave anything off for an inside mount. Record the true window opening and we apply every fit deduction in our shop, matched to the product and how it's built. It's the difference between a shade that fits and one that's a half-inch short — and it's the most common mistake people make measuring on their own. Give us the real numbers. Fit is on us.
No pressure to be perfect
Just need a quote? Rounded sizes are fine
For a quote, approximate measurements are all we need — round to the nearest inch and note which windows. We firm up the exact sizes before anything is built. Motorized shades, very wide windows, and specialty installs get a free professional measure either way, so the size is right before production. One team measures, builds, and installs — so the fit is always our responsibility, not yours.
Send us your sizes
For each window, send the width × height, the mount type (inside or outside), the room, and how much light you want — solar, light-filtering, or blackout. We'll come back with products, fabrics, and lead times.
Request a QuoteFaster quote: include your window count, rough sizes, and whether you need solar, light-filtering, or blackout.
Printable measuring guide + worksheet
A one-page guide with the steps, the diagrams, and a worksheet to record every window. Print it, measure, and send us the sheet.
Download the Guide (PDF)Prefer we handle it? We measure for you
Our crew measures, builds, and installs — one accountable team from the first measurement to the final shade. Every product passes the HT Five-Point Check and is backed by the HT Worry-Free Warranty. Tell us about your windows and we'll take it from there.
Measuring questions
How do I measure for inside-mount blinds?
Measure the window width in three places — top, middle, and bottom — and record the smallest. Measure the height in three places — left, centre, and right — and record the largest. Round to the nearest 1/8" and send the exact opening; HT Blinds applies the fit deductions in the shop.
Should I subtract anything for an inside mount?
No. Give us the exact window opening and we make every fit deduction ourselves. Subtracting on your own is the most common measuring mistake and usually leaves the shade too small.
What if my window isn't perfectly square?
Most aren’t, which is why you measure in three places. For an inside-mount width use the smallest reading; for the height use the largest. That guarantees the shade clears the tight spots and covers the full opening.
How precise do my measurements need to be for a quote?
For a quote, rounded measurements are fine — to the nearest inch is enough. HT Blinds confirms the exact sizes before anything is built, and motorized, very wide, or specialty installs get a free professional measure.
Do you measure for me?
Yes. Our crew can measure for you — the same team that builds and installs your shades. Measuring yourself is optional and only there to speed up your quote.
Inside mount or outside mount — which should I choose?
Choose inside mount for a clean, built-in look when the frame has enough depth. Choose outside mount to block more light around the edges, cover an uneven frame, or make a window look larger. If you're unsure, outside mount is the safe default.