How to Measure for Blinds and Shades

Abigail Sawyer | 19 Oct 2015 | How To

If you know you need new window treatments, decided on a style and have ordered free samples to compare colors, the next step is to measure your windows.

No two windows are alike and hardly any are perfectly square, so it's important to measure precisely for an exact fit. We'll tell you how to measure for blinds in a few easy steps.

Note: These instructions apply to most products, including wood blinds, faux wood blinds, mini blinds, roman shades, roller shades, solar shades, sheer shades, cellular shades, woven wood shades, and pleated shades. If you're ordering shutters, draperies, vertical blinds, arch window shades, blinds for doors, bay windows or other specialty situations, we have links at the bottom of this post to more detailed instructions.

You Got This!

We believe that anyone can measure their own windows, and save some money by flexing their DIY muscles. Nervous about getting it wrong and being stuck with blinds that don't fit? Don't worry! We've got your back with our SureFit Guarantee! surefit logo

With the SureFit Guarantee, if your window treatments don't fit for any reason (your fault or ours), we'll remake them at no cost to you. Learn More.

Gather Your Tools

To get a perfect fit, it's important to have accurate measurements, and a steel measuring tape is the only way to do that. Yard sticks or cloth measuring tapes just won't cut it.

Steel Measuring Tape

When you measure, be sure to round to the nearest 1/8 inch. If it's been a while since you've used a measuring tape, here's a handy cheat sheet.

how to read a tape measure

Print the Measuring Worksheet

The other thing you'll need is our handy measuring worksheet.

View the Measuring Guide Horizontal Measuring Guide

Choose a Mount - Inside or Outside?

Window treatments can be mounted 2 ways - inside mount and outside mount. You must decide which one you'll be using before you measure or place your order.

With an inside mount the blinds are mounted inside the window frame with the brackets screwed into the top of the casing.

For an outside mount, the blinds are mounted to the front of the window frame or the wall above the window. Outside mount blinds or shades will need to be larger to cover the entire window frame.

side by side of outside mount and inside mount blinds

In 90% of cases we recommend an inside mount. It gives a cleaner look, shows off your window casing, and will block more light.

It's only necessary to choose an outside mount if you can't mount inside the frame because of obstructions like window cranks and alarm sensors, or if your windows doesn't have enough depth.

Want to know if you have adequate depth? On the product page under the "Measuring and Install Specs" tab, you'll find the Minimum Inside Mount Depth. If your window is shallower than the number listed there, you'll need to choose an outside mount or consider another product.

measure mount

Now that you've decided on a mount, follow the respective instructions.

How to Measure for Inside Mount Blinds and Shades

how to measure for inside mount blinds

1. Measure the Width

Start by measuring the width of your window inside the frame in 3 places - top, middle and bottom. Record each of these on your worksheet. Circle the narrowest of these measurements. That'll be the width you use when you order.

Do not make any deductions to this number. The factory will take off exactly as much as they need to allow your window treatments to raise and lower without scraping the sides of your windows.

how to measure for inside mount blinds

2. Measure the Height

Measure your height from the window sill to the top of the window opening in 3 places - left, center and right. Record these measurements on your worksheet. Circle the tallest of these measurements. That's the height you'll use to place your order.

Again, don't make any deductions. Tell us the exact size of your window opening.

How to Measure for Outside Mount Blinds and Shades

how to measure for outside mount blinds

1. Measure the Width

Outside mount blinds or shades can be mounted 2 ways - to the trim around your window, or to the wall above the window opening (like the photo above).

If you're mounting to the trim, measure the width of the trim at the top of the window.

If you're mounting to the wall, measure the width you'd like the blinds or shades to be. We recommend adding at least 2 or 3 inches to the width of the window opening. (see photo above)

The factory will not make any deductions to your measurements, so give us the exact size you'd like your window treatments to be.

how to measure for outside mount blinds

2. Measure the Height

If your window has a protruding sill, measure the height starting at the sill and up to 3 1/2 inches beyond the top of your window opening to allow room for the mounting hardware. This is your height.

If your window does not have a protruding sill (like the photo above), we recommend that you start your measurement 2 or 3 inches below your window opening. Also add 3 1/2 inches to the top. In total you'll be adding about 6 1/2 inches to the height of your window opening.

Need Help Measuring?

If you have any questions, or want someone to guide you through the process, designers are available to help at 800-505-1905. We also have great videos that you can follow along with as you're measuring.

Be sure to check out more resources on our Measuring page. You can also find specialized measuring instructions on each product page under the measuring and install specs tab.

measuring instructions prod page

Also, check out our additional measuring guides:

How to Measure for Roman Shades

How to Measure for Roller Shades

How to Measure for Mini Blinds

How to Measure for Wood Blinds

How to Measure for Cellular Shades

How to Measure for Angle Top and Angle Bottom Shades

Specialized Measuring Instructions

How to measure for blinds

As we mentioned earlier, not all products conform to the measuring instructions above. Follow the links below to see more detailed instructions for these applications.

Vertical blinds - Measure width as instructed above - top, middle and bottom, choose the narrowest. When measuring the height, measure left, middle and right, choose the tallest. This allows all the vertical vanes to hang evenly

Shutters - You'll need to check your window for squareness to determine if you use an inside mount or outside mount.

Draperies - There are several other considerations with custom draperies like fullness, how much of the window you want exposed, puddling and more.

Arch Window Shades - Unless your window is a perfect arch (height is half the width), we'll have you create a paper template of your window. It's best to give us a call at 800-505-1905 for designer help on this one.

Blinds for Doors - Depending on your trim and door size, there are a few other things to consider when you measure for blinds on doors.

Bay Window Blinds - Some bay windows have angles that cause blinds to intersect of not ordered properly. We've got detailed instructions to help you get it right.

When to Call A Pro

professional blinds measuring

If you have lots of windows, windows out of reach, odd shapes or are ordering shutters - it might be worth it to have a professional measure for you. You can find someone in your area by visiting our Find a Pro page. Pricing varies, but professional measuring starts at about $90 - $125.

More Questions?

Don't be shy! Tweet to us @BlindsDotCom or give us a ring at 800-505-1905.

  • About Author

    Abigail Sawyer is a Senior Social Media Specialist for She's a home improvement junkie who is currently restoring a 1972 cottage with the help of her husband and goldendoodle, Biscuit. Walking in the footsteps of Martha Stewart, she’s happiest when she’s crafting or whipping up a new recipe; although nothing beats curling up with a good book and some Girl Scout Cookies. Follow her on twitter + instagram at @whatabigailsaw