How Much Smaller Should Blinds Be Than the Window?

a wooden kitchen table and chairs next to a window


Your home may look awkward if your blinds aren’t the right size for your window. Many homeowners are confused about how much smaller blinds should be than the window. To accurately measure the size of blinds you need for the windows in your home, you must diligently measure all windows correctly. You cannot assume all windows are the same size because they appear similar to the naked eye. 

To ensure the blinds and shades you order fit properly, take accurate measurements using a marker, steel measuring tape and a notepad.

a person installing modern blinds

Source: ellinnur bakarudin/ 

How to Measure Your Window Correctly for Inside or Outside Mount

You need to decide whether to mount the blinds on the inside or outside of your window frame before measuring your windows and learning how to take down blinds

Inside Mount

Blinds installed inside the window frame give the house a clean, well-polished appearance. When mounted on the inside of the frame, your blinds will fit perfectly inside the window.

As a result of the positioning, you can see the window’s size and the moldings on its frame. The window frame should have enough depth to accommodate a precise blind fit on the cornice. Different blind styles require varying depths for a proper fit. 

Outside Mount

It’s not a problem if your window’s depth does not allow a flush fit. You only need a small gap between the blind beam and the inside window frame. Blinds installed outside the window frame help give an expansive appearance and hide unsightly openings in the trim.

If you decide to mount the blinds outside, you can get a more precise fit on the window molding. Outside blinds allow for better light management and increased privacy. Outside blinds are your best option if you wish to cover the entire window, including the frame, rather than just the glass.  

Our Vertical Blinds Are Great for Large Windows

a couple measuring a window

Source: Sergey Peterman/ 

How to Measure Windows for Vertical Blinds

Vertical blinds are the perfect choice for windows that stretch from one wall to another, doors or patios. 

Inside-Mounted Vertical Blinds

To measure for inside-mounted vertical blinds, start by measuring the length of the window in three places. Begin at the top of the window and end at the sill; use the smallest measurement for the blind’s length. 

Those who work in the home improvement industry make approximations of half an inch or quarter of an inch, so measure the exact height in the same manner. That is the sum of the first three-dimension measurements taken from the top sill. Take two diagonal measurements of the window, one from each corner. 

If the inside of the window frame has unequal measurements, opting for an outside mount will increase the attractiveness of the blind and improve light control.

Outside-Mounted Vertical Blinds

To measure for an outside-mounted vertical blind, you can measure the width of the sides in three places, taking the smallest as your accurate measurement. Don’t forget to measure the window from top to bottom. Start at the sill if there is one. Record the height of the window accurately, including any brackets or moldings you may have. 

Add three inches to the measurement to ensure sufficient mounting space. Deduct half an inch from the blind’s height when it extends beyond the frame.

Need Mini Blinds? Browse Our Options!

How to Measure for Mini Blinds

Many people use mini blinds for smaller windows, such as those adjacent to or on both sides of a door. Mini blinds are considered the smaller version of the venetian blinds, and they provide the same level of light control and privacy. They do not have any heavy hardware, so they will look clean and modern on any window. 

Inside-Mounted Mini Blinds

Measure the depth of the frame where you intend to attach the brackets. Measuring the depth of your window frame from the front of the wall to the glass will allow you to determine if your window depth meets the minimum requirement of the inner mount.

To calculate the window width, measure the width of each opening at the top, the middle and the bottom. Use the narrowest measurement from these three measurements. This is the measurement you will send to the factory for the window’s width.

Your window opening’s height should be measured in three spots: left, center and right. Use the tallest measurement for the blind’s height.

Outside-Mounted Mini Blinds

Measure how much space you want to cover, including the overlap of the blind around the window. You can add up to three inches to this measurement for maximum privacy and light control. Measuring the window from the top to the bottom of the sill will give you its height. 

Selecting the Best Blinds for Your Window

It may seem blinds are a minor feature in your house, but they can be an essential source of energy efficiency and privacy. With some patience and time spent accurately measuring your windows, you can ensure your blinds fit your windows well for a beautiful aesthetic in your home. Explore our website to find the perfect look for your home. Whether you want cordless, blackout or vertical blinds, we have all the options to meet your needs.

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