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Most people grab a tape measure, jot down a number, and place their order. Then the blinds arrive and either the fit is off or there is a gap on the sides that lets in more light than expected.
The measurement step is where most window blind purchases go wrong and it is entirely avoidable.

Here are a few things that you need to know before you measure, so your new window blinds in Edmonton fit the way they should.

Why Getting the Right Measurement Matters 

A blind that is even half an inch too narrow will not cover the window properly. One that is too wide will not sit flat. For blackout blinds in Edmonton, even a small gap on the sides defeats the entire purpose. For honeycomb blinds in Edmonton, a poor fit means the insulation benefit you are paying for is partially lost through the edges.

Measuring correctly is not complicated. But it does require knowing which measurement to take and from where.

The First Decision: Inside Mount or Outside Mount

Before you take a single measurement, decide how you want the blind to sit.

• Inside mount means the blind fits inside the window frame, within the recess. It gives a clean, built-in look and works well for roller blinds in Edmonton, zebra blinds, and honeycomb blinds. For an inside mount, you need a window recess deep enough to hold the headrail without it sticking out.
  
• Outside mount means the blind is fixed to the wall or window frame above and outside the opening. This is the right choice when your window recess is too shallow, when you want the window to appear larger, or when using vertical blinds in Edmonton on a wide sliding door.

The type of mount changes where and how you measure, so settle this first.

How to Measure for an Inside Mount

This is where most people make the most common mistake - measuring only once, or measuring in the wrong spot.

• Width: Measure across the window opening in three places - at the top, the middle, and the bottom. Windows are often not perfectly square, especially in older Edmonton homes. Use the smallest of the three measurements. This ensures the blind will actually fit inside the frame without jamming.
  
• Height: Measure from the top of the window opening down to the sill in three places - left side, centre, and right side. Again, use the smallest measurement.

When ordering, most blind companies in Edmonton will deduct a small amount from your width measurement to allow the blind to operate smoothly inside the frame. This is called a fabrication deduction, and a good supplier will apply it automatically. Ask before you order if you are unsure.

For inside mount specifically:

• Use the smallest after measuring the width at top, middle, and bottom
• Use the smallest after measuring the height at left, centre, and right
• Do not subtract anything from your measurements; let the manufacturer handle deductions
• Check that your recess is deep enough for the headrail (typically at least 2–3 inches)

How to Measure for an Outside Mount

The outside mount gives you more flexibility because you are deciding where the blind goes, not fitting it into an existing space.

• Width: Add at least 3 inches on each side of the window opening, so 6 inches total to the actual window width. This overlap blocks side light effectively and makes the window appear wider. For blackout blinds or window shades in Edmonton where full light block matters, add even more.
  
• Height: Measure from where you want the top of the blind to sit, usually 3 to 4 inches above the window frame, down to where you want it to end. For full coverage to the sill, measure to the sill. For floor-length coverage on a patio door, measure to the floor.

For outside mount specifically:

• Add at least 3 inches to each side of the width
• Add 3 to 4 inches above the frame for the height starting point
• For light-sensitive rooms, go wider rather than narrower on the overlap

Measuring for Specific Blind Types

Different blinds have some additional things to keep in mind when measuring.

• Zebra blinds in Edmonton are almost always inside mount and work best when the recess is deep enough so the roller does not protrude. Measure the full inside width and confirm the recess depth before ordering.
  
• Vertical blinds in Edmonton are measured differently from most. Width is measured horizontally across the full span you want covered. Height is measured from the headrail position down to just above the floor, typically leaving a gap of half an inch so the vanes do not drag.
  
• Roller blinds in Edmonton follow standard inside or outside mount rules. If you are going double roller, confirm that the recess depth can accommodate two separate headrails side by side.
  
• Horizontal blinds in Edmonton, including mini blinds, are measured just like standard roller blinds. The key thing to check is the minimum width the blind can be ordered in, as very narrow windows sometimes have limitations.
  
• Window shutters in Edmonton require the most detailed measurement. Shutter frames are custom-built to your window, so any error gets built into the product. Measure width and height at multiple points and note the shallowest recess depth, this determines the frame type needed.
  
• Roman blinds are measured the same as standard inside or outside mount, but the fabric stack at the top when raised needs to be factored into the usable height. If you want the full window exposed when the blind is up, add the stack height to your starting position above the frame.
  
• Bay windows work best when each section is measured and ordered individually rather than trying to cover the bay with a single blind. Measure each flat panel separately, inside mount, and treat them as individual windows.

The Tool You Actually Need

A steel tape measure is all you need. Not a fabric tape, not a laser measure for this purpose, a standard retractable steel tape gives the most accurate reading at the window recess.

Measure in inches if your supplier uses imperial sizing, which most blind companies in Edmonton do. Always write down your numbers immediately and double-check them before placing any order.

If you are measuring multiple windows in the same room, label each measurement clearly, left window, right window, bay left panel, so nothing gets mixed up at the order stage.

Measure Twice, Order Once

A wrong measurement wastes time and money. Custom blinds in Alberta are cut to the size you provide, which means there is no adjusting after the fact. Getting it right from the start means your window blinds fit properly, look clean, and do their job.

If you are not confident in your measurements or if your windows are an unusual shape, do not guess.

At Sun Blinds Inc., we offer free in-home consultations where we measure every window for you before a single order is placed. Whether you are looking at roller blinds, honeycomb blinds, zebra blinds, shutters, or vertical blinds in Edmonton, our team takes the guesswork out of the process entirely. Precise measurements, factory direct price blinds in Edmonton, and a lifetime warranty, that is what we bring to every home.