How to Measure for Blinds: Step-by-Step Guide

Written by Stuart G., Founder and Director at Direct Order Blinds, manufacturing made-to-measure blinds in Boston, Lincolnshire since 2005.

A blind is only as good as its fit. Get the measurements right, and you'll have a clean, professional finish that works exactly as it should. Get them wrong, and even the best fabric will look and perform badly. Here's exactly how to do it. If you haven't settled on a blind type yet, our types of blinds guide is worth reading first.

Recess or Outside Fitting: Know the Difference First

Before you pick up a tape measure, decide how the blind will be fitted.

• Inside recess means the blind sits within the window recess itself, giving a neat, built-in look.

• Outside recess means the blind is fixed to the wall or frame above and outside the window recess, covering the whole opening and a little extra on each side.

This decision changes how you measure, so confirm it first.

What You'll Need

• A steel tape measure (not fabric, which can stretch and throw off your figures)

• A notepad or your phone, to record each measurement as you go

• A pencil for marking bracket positions, if you're measuring ahead of fitting

Step-by-Step: How to Measure

1. Measure the width first. For an inside recess, measure the recess width at the top, middle, and bottom of the window. Windows are rarely perfectly square, so use the smallest of the three measurements to make sure the blind fits.

2. Measure the drop (height). Measure from the top of the recess to the sill at the left, middle, and right. Again, use the smallest measurement for an inside recess fit.

3. For an outside recess fit, measure the full width and height you want the blind to cover, ensuring you add a few cm above and to the sides of the window recess for the best coverage. There's no need to take the smallest measurement here, since the blind sits outside the recess, and you should order as “exact” or “blind size” since you are measuring the size of blind you want. 

4. Record every measurement in millimetres, and double-check by measuring a second time before you order.

Measuring each window twice, or having someone else check your measurements, will ensure a smooth ordering and fitting process.

Measuring for Specific Blind Types

Roller Blinds

For an inside recess Roller Blind, take the smallest width measurement across the recess. The depth of the recess matters too. You'll need at least 70mm of depth for the roller mechanism to sit properly and be sure to allow for window handles, tiles and dado rails too. 

Venetian Blinds

Measure the same way as a standard inside or outside recess fit. Venetian Blinds need a similar recess depth to roller blinds, so check for obstructions like handles or tiles before ordering. 

Vertical Blinds

Vertical Blinds are almost always fitted inside the recess. Again, consider the depth of the recess and check there is enough room for window handles. Where looking to fit in a recess where doors or windows open inwards, it is vital to think about how the vertical blind headrail might obstruct the opening.

Common Measuring Mistakes to Avoid

• Measuring in only one spot. Always check top, middle, and bottom (or left, middle, right) since windows are rarely perfectly uniform.

• Using a fabric tape measure, which stretches and gives inaccurate results.

• Forgetting to check for obstructions like handles, hinges, window locks or tiles that could interfere with the blind once fitted.

• Rounding measurements up or down. Record the exact figure in millimetres where possible.

What If Your Window Isn't a Standard Size?

This is exactly what made-to-measure is for. Every blind we make is manufactured to your exact measurements, whether that's an unusually narrow window, a bay, or an odd-shaped recess. There's no need to compromise on a standard size that doesn't quite fit. Our best blinds for bedroom guide has a specific section on measuring bay windows if that's what you're working with.

Use our made-to-measure blinds service for a perfect fit every time. If you're fitting a bifold, or a tilt-and-turn window or door, take a look at FITtoFRAME Blinds or Perfect Fit® Blinds, both designed to click into place without drilling.

FAQs

Should I measure the recess or the whole window for an inside fit?

Measure the recess itself, at three points, and use the smallest measurement.

How much extra should I add for an outside recess fit?

Around 50 to 100mm on each side and above the window is standard, though this can vary depending on how much light coverage you want.

What if my window frame has a handle or hinge in the way?

Check for obstructions before measuring and ordering. No-drill options like Perfect Fit or Intu Blinds are worth considering if a standard recess fit won't clear the hardware.

Can I get blinds made for a non-standard window size?

Yes. Every blind we manufacture is made to your exact measurements. 

Still unsure about a tricky window?

Order up to 10 free fabric samples and we'll help you get the measurements and fabric choice right before you commit.