How To Measure For Window Blinds

Measuring your windows is something you can do without any prep. It’s pretty easy once you know exactly what you need to measure. Unfortunately, it’s not as easy as running a measuring tape from one corner to another. It depends on where you’re hanging the mount, windows or door hangings, and what types of window coverings you’re getting! Here is a guide for how to measure for window blinds.

Measuring For Inside Window Mounts

An interior mount is one that is fitted inside the window frame. There are a few things you should remember when you’re looking to add interior mounts to your window. 

First, do not deduct anything from your measurements. Take the exact measurements and write them down. Your design specialist or window treatment supplier will know if any deductions will need to be made based on the product. 

Second, double-check all of the mounting requirements of your chosen blinds to ensure that your window is deep enough to accommodate an interior mount. If it’s too shallow, you’ll need to choose an outside mount or switch to another product.

Thirdly, make sure you’re using a flexible measuring tape so you can get it flush against the frame. This helps ensure accuracy. 

Finally, remember to measure everything! Even if you don’t need a specific measurement, it will be better to have it in case you need to switch products. 

How to Measure for an Interior Mount

To get an accurate measurement for your interior mount, follow these steps: 

1. Put your measuring tape in the top left corner and drag it until it’s flush with the top right corner. Mark down the measurements. 
2. Go halfway down the window and measure from the middle of the frame, to the opposite end. Mark down the measurements. 
3. Finally, measure the bottom left corner to the bottom right corner. Mark down the measurements. 
4. Compare the three measurements you made above. The narrowest of the three will be the size you’re going to need. Round it to the nearest ⅛ inch. 
5. Measure the height of your window following the same format — measure the right side, the height at the center, and the height at the left side of the frame. Make sure your measuring tape is flush with the sill and the top of your window frame. Mark each measurement down and compare them. Take the longest of the three measurements. 
1. If you prefer to keep the blind from resting on the sill deduct a 1/4" from the height. 
2. If your window does not have a sill, measure to the point you would like the blind to reach.
6. Finally, measure the window’s diagonal on both sides. Start on the top left and measure down to the bottom right corner. Mark down the measurement. 
7. Then start at the top right and measure to the bottom left. Compare the two measurements.
1. If the two diagonal dimensions differ significantly, it may be necessary to order an outside mount for optimal light control and privacy. 

How to Measure For Outside Mounts

Outside mounts are ones that are outside of your window frame. Think of them like curtain rods or valences — they’re meant to hug the outside of the window frame to add depth. Measuring these is a little more difficult, as you don’t have set boundaries. However, you’ll require less measurements. 

Here’s how you do it. 

1. Measure the distance from the outermost points you would like the blind to cover. 
1. To minimize light leakage the blind should overlap the window opening by at least 1 1/2" on each side for a total of 3" on the entire width.
2. Measure distance from where the top of the blind will be located to the window sill. 
1. The blind should overlap the window opening on the top by at least 1-1/2". Some products may require more than 1-1/2" above the window for mounting hardware. 

How to Measure for Vertical Window Blinds

You’re going to measure slightly differently for vertical blinds for both inside and outside mounts. 

Inside Mount For Vertical Blinds

1. Measure the width inside the window opening at the top, and round down to the nearest 1/8" measurement.
2. Measure the height inside the window opening from the top of the window opening to the window sill three times. 
1. Measure once on the left, at the center, and on the right and take the shortest of the three measurements, and round down to the nearest 1/8" measurement.

Outside Mount For Vertical Blinds

1. Measure the distance from the outermost points you would like the blind to cover. 
1. To minimize light leakage and ensure privacy the blind should overlap the window opening by 4" on each side for a total of 8" on the entire width.
2. Measure distance from where the top of the blind will be located to the window sill. 
1. The blind should overlap the window opening on the top and the bottom by at least 3". 
3. If the blind will hang to the floor, take a 1/2" deduction on the height to allow for operating clearance.

Measuring Vertical Blinds for Patio Doors

Patio doors can be a little difficult to measure due to their size. If you can, get a friend to help.

1. Measure the distance from the outermost points you would like the blind to cover. 
1. To minimize light leakage and ensure privacy the blind should overlap the window opening by 4" on each side for a total of 8" on the entire width. 
2. Consider the size of the vertical blind stack. Allow sufficient overlap for easy access through the door. 
3. Measure distance from where the top of the blind will be located to the floor on the left side, center, and right side of the window. 
1. The blind should overlap the window opening on the top by at least 3". 
4. Take a 1/2" deduction on the height to allow for operating clearance.

Or let the professionals do it for you. At Budget Blinds of Tempe, we’re passionate about working with you to turn your house into your dream home. From the initial design consultation to professional installation, we’re ready to help you every step of the way. Give us a call to get started.