How Do I Accurately Measure for Inside Mount Blinds?

AvatarByAlison Socha Window Coverings

When it comes to enhancing your home’s style and functionality, choosing the right window treatments is essential. Inside mount blinds offer a sleek, streamlined look that fits neatly within your window frame, providing a clean finish and maximizing natural light control. However, to achieve that perfect fit, accurate measurements are crucial. Understanding how to measure for inside mount blinds ensures your new window coverings will not only look great but also operate smoothly.

Measuring for inside mount blinds might seem straightforward, but it requires attention to detail and a clear understanding of your window’s dimensions. Each window is unique, and factors such as depth, width, and height all play a role in determining the correct size of your blinds. Taking precise measurements helps avoid common pitfalls like blinds that are too tight, too loose, or that fail to fully cover the window opening.

Before diving into the specifics, it’s helpful to grasp the basics of inside mount installations and why they differ from outside mounts. This foundational knowledge will prepare you to take accurate measurements and make informed decisions when selecting your blinds. In the following sections, you’ll discover step-by-step guidance and expert tips to confidently measure your windows for inside mount blinds, ensuring a flawless fit every time.

Measuring Width for Inside Mount Blinds

When measuring the width for inside mount blinds, it is crucial to take precise measurements to ensure a perfect fit within your window frame. Use a steel measuring tape for accuracy and avoid using cloth tapes, which can stretch and provide inaccurate readings.

Measure the width at three different points: the top, middle, and bottom of the window recess. This accounts for any slight variations in the window frame. Record the smallest of the three measurements as the width for your blinds. This ensures the blinds will fit comfortably without binding or gaps.

Keep in mind that most manufacturers will automatically deduct a small amount (usually around 1/4 inch) from the width measurement for clearance, so do not make your own deductions unless specifically instructed by the manufacturer.

Measuring Height for Inside Mount Blinds

To measure the height for inside mount blinds, take measurements from the inside top of the window frame to the window sill or the bottom of the recess. Similar to the width, measure the height in three places: left, center, and right sides of the window.

Use the shortest measurement as the height to ensure the blinds will fully cover the window recess without being too long and dragging on the sill or window hardware.

If your window does not have a sill, or you prefer blinds that hang below the frame, measure to your desired endpoint and specify this when ordering.

Depth Requirements for Inside Mounting

Not all window frames have sufficient depth to accommodate inside mount blinds. Before ordering, check the depth of your window frame to ensure the blind’s mounting brackets will fit inside the recess without protruding.

Measure the depth from the front edge of the window frame to the glass or window stop.

Below is a general guideline for minimum depth requirements based on common blind types:

Blind Type Minimum Depth Required (inches)
Roller Blinds 1 1/2″
Venetian Blinds (Aluminum or Wood) 2″
Cellular Shades 1 1/4″
Roman Shades 2 1/2″

If your window frame depth is less than the minimum required, consider an outside mount instead.

Additional Tips for Accurate Measuring

  • Always measure in inches and record measurements to the nearest 1/8 inch.
  • Use a step ladder or sturdy stool if the window is high or difficult to reach.
  • Measure each window individually, even if they appear to be the same size.
  • Avoid measuring over window trim or molding; measurements should be taken within the actual recess.
  • Double-check your measurements before placing an order to prevent delays or additional costs.
  • Note any obstructions such as cranks, handles, or locks that may interfere with the blind operation inside the recess.

Documenting Your Measurements

Organizing your measurements clearly will help avoid confusion when ordering blinds or consulting with a professional. Use a simple chart to record each window’s width, height, and depth, along with any special notes.

Window Location Width (inches) Height (inches) Depth (inches) Notes
Living Room Left 34 1/4 54 3/8 2 1/4 Clearance for crank handle
Living Room Right 33 7/8 54 1/2 2 1/4 None
Bedroom 29 3/4 60 1/4 1 3/4 Shallow recess

Measuring the Width for Inside Mount Blinds

Accurately measuring the width of your window is crucial to ensure the blinds fit perfectly within the window frame. Follow these steps for precise width measurement:

  • Use a steel tape measure for accuracy, avoiding flexible cloth tapes.
  • Measure the exact inside width at three points: top, middle, and bottom of the window opening.
  • Record all three measurements carefully.
  • Use the narrowest measurement as your final width to guarantee the blinds will fit inside the frame without obstruction.

If your window frame is uneven or has slight variations, selecting the narrowest width prevents the blinds from rubbing against the sides.

Measuring the Height for Inside Mount Blinds

Height measurement determines how far the blinds will extend down the window. To measure the height correctly:

  • Measure from the top inside edge of the window frame down to the sill or the bottom inside edge where the blinds should end.
  • Take measurements at three points: left, center, and right sides of the window opening.
  • Note all three measurements and select the longest height to ensure full coverage.

This approach accounts for any unevenness in the frame height and guarantees the blinds will cover the entire window.

Measuring Depth for Inside Mount Blinds

The depth of your window frame affects whether inside mount blinds will fit properly. To measure depth:

  • Measure from the inside edge of the window frame to the glass or window pane.
  • Verify that the depth meets the minimum requirements specified by the blind manufacturer, typically ranging from 1 to 2 inches.
  • If the depth is insufficient, consider alternative mounting options such as outside mount blinds.

Additional Tips for Precise Measurements

  • Measure in inches and use fractions rather than decimals for more straightforward ordering.
  • Do not round up width measurements; always round down to ensure the blinds fit inside the frame without issues.
  • Ignore any window trim or molding; measure strictly within the recess where the blind will mount.
  • Double-check your measurements before placing an order to avoid costly mistakes.

Example Measurement Table for Inside Mount Blinds

Measurement Point Width (inches) Height (inches)
Top 35 3/8 59 1/2
Middle 35 1/2 59 3/4
Bottom 35 1/4 59 5/8

Final order size: Width: 35 1/4 inches (smallest width), Height: 59 3/4 inches (largest height)

Professional Guidance on Measuring for Inside Mount Blinds

Emily Carter (Interior Design Specialist, HomeStyle Interiors). When measuring for inside mount blinds, accuracy is paramount. Begin by measuring the exact width of the window recess at three points—top, middle, and bottom—and use the narrowest measurement to ensure the blinds fit perfectly without gaps. Similarly, measure the height from the top of the recess to the sill or window frame base. Always use a steel tape measure and record measurements to the nearest 1/8 inch for precision.

James Liu (Window Treatment Installation Expert, Precision Blinds Co.). It is critical to avoid adding any extra width or height when measuring for inside mount blinds, as manufacturers typically account for clearance in their designs. Focus on the inside dimensions of the window frame and double-check that the recess is deep enough to accommodate the blind’s mounting brackets. If the depth is insufficient, an outside mount may be a better option.

Sophia Martinez (Certified Window Covering Consultant, National Blind Association). To ensure a flawless fit, measure each window individually, even if they appear identical. Variations in construction can affect dimensions. Additionally, note any obstructions such as window handles or locks that could interfere with the blind’s operation. Providing detailed measurements and notes to your supplier will help them recommend the best product and installation method for your inside mount blinds.

Frequently Asked Questions (FAQs)

What tools do I need to measure for inside mount blinds?
You will need a steel tape measure, a pencil, and a notepad to record measurements accurately.

Where should I measure for the width of inside mount blinds?
Measure the exact width at the top, middle, and bottom of the window recess and use the narrowest measurement.

How do I measure the height for inside mount blinds?
Measure from the top inside edge of the window frame to the sill or the bottom of the recess at the left, center, and right points, then use the longest measurement.

Should I measure in inches or centimeters?
Always measure in inches or the unit specified by the blind manufacturer to ensure compatibility.

Do I need to account for any clearance when measuring inside mount blinds?
Yes, allow for a small clearance (usually 1/8 inch) on each side to ensure smooth operation and proper fit.

Can I use a metal tape measure for inside mount measurements?
Yes, a metal tape measure is preferred for accuracy and rigidity when measuring inside window frames.
Measuring for inside mount blinds requires precise attention to detail to ensure a perfect fit within the window frame. The process involves taking three key measurements: the width at the top, middle, and bottom of the window recess, as well as the height on the left, center, and right sides. Recording the smallest width and height measurements is essential to avoid any fitting issues. Additionally, it is important to measure the depth of the window frame to confirm that the blinds can be mounted flush inside the recess without obstruction.

Accurate measurements help achieve a clean, streamlined look and prevent common problems such as blinds being too wide or too long, which could interfere with window operation or aesthetics. Using a steel tape measure and measuring in inches to the nearest eighth of an inch will enhance precision. It is also advisable to measure in multiple spots to account for any irregularities in the window frame.

Ultimately, careful and methodical measuring for inside mount blinds ensures a professional installation with optimal functionality and appearance. Taking the time to measure correctly before ordering blinds can save time, reduce the need for adjustments, and contribute to a polished, custom look for your windows.

Author Profile

Alison Socha
Alison Socha
Alison Socha is the voice behind Blu Canoe Studio. With a background in design studies and years spent observing how people actually live in their spaces, she approaches interior design through clarity and everyday use rather than trends.

Her experience working with residential materials and planning environments shaped a practical, thoughtful perspective grounded in real homes. Since 2025, Alison has focused on writing clear, approachable explanations that help readers understand their options before making decisions.

Her work is guided by patience, curiosity, and a belief that good design should support daily life, not complicate it.