How to Measure Inside Mount Window Shades

Inside mount window shades are one of the most popular choices for homeowners– and for good reason. They create a clean, built-in appearance while helping your windows look polished and streamlined.

In this guide, we’ll walk you through exactly how to measure for inside mount cellular shades so your custom window treatments fit beautifully– the first time!

What Are Inside Mount Window Shades?

Inside mount shades are installed inside the window frame rather than overlapping the trim or wall around the window. The mounting brackets attach to the inside-top of the frame, allowing the shade to sit neatly within the opening.

This style is popular because it:

• Creates a clean, modern look
• Shows off decorative window trim
• Helps shades sit flush with the window
• Provides a more tailored appearance

Before You Start Measuring

Before taking measurements, make sure your window frame has enough depth to support an inside mount installation.

For most inside mount cellular shades, you’ll need:

• A minimum of 1 1/4 inches of flat mounting surface
• A steel tape measure for accuracy
• Measurements recorded to the nearest 1/8 inch

We recommend avoiding cloth measuring tapes, as they can stretch and create inaccurate measurements.

Step 1: Measure the Width

To measure the width for inside mount window shades:

1. Measure from the inside-left edge of the window frame to the inside-right edge
2. Take measurements in 3 locations:
   • Near the top
   • Near the middle
   • Near the bottom
3. Round each measurement down to the nearest 1/8 inch
4. Use the smallest of the three measurements

Why Use the Smallest Width Measurement?

Not all windows are perfectly square. Using the narrowest width makes sure your custom shade will fit properly within the frame without rubbing or catching on the sides.

Step 2: Measure the Height

Next, measure the height of the window opening.

1. Measure from the inside-top of the frame down to the bottom sill
2. Take measurements in 3 locations:
   • Left side
   • Center
   • Right side
3. Round each measurement up to the nearest 1/8 inch
4. Use the largest of the three measurements

Why Use the Largest Height Measurement?

Using the tallest measurement ensures your shade fully covers the window opening for better light control and privacy.

Deductions Are Not Your Friend!

One of the most common mistakes homeowners make is subtracting space from their measurements.

We strongly recommend not making deductions yourself, as the necessary deductions are made during production by our team to create the proper fit inside the window frame.

Tips for Accurate Measurements

For the best results:

• Measure carefully and double-check your numbers
• Always use a steel tape measure
• Record measurements in inches and 1/8-inch increments
• Measure each window individually, even if they appear identical
• Avoid estimating or rounding excessively

Inside Mount vs. Outside Mount Shades

Inside mount shades sit within the frame for a sleek appearance, while outside mount shades are installed outside the opening and typically provide more light blockage.

Inside mount shades are ideal when:

• You want a clean, modern aesthetic
• Your window frame has enough depth
• You want to showcase decorative trim

Outside mount shades may be better if:

• Your window opening is shallow
• You want maximum blackout coverage
• Your windows are slightly uneven

At EcoSmart Shades, every shade is custom-made to fit your windows precisely. Accurate measurements aid in smooth operation, better insulation, and a polished final look.

Need help measuring your windows? Don’t hesitate to reach out to our team of Shade Gurus for additional tips and tricks!