
Choosing the right window blinds can transform a room, but it all starts with accurate measurements. Don’t worry, it’s easier than you might think! This comprehensive guide will walk you through the process, ensuring a perfect fit for your windows.
Why Accurate Measurements Matter
Getting the measurements right is crucial for several reasons:
- Perfect Fit: Blinds that fit perfectly enhance the look of your windows and room.
- Proper Functionality: Correct measurements ensure your blinds operate smoothly.
- Avoid Costly Mistakes: Accurate measurements prevent the need for returns or alterations.
Tools You’ll Need
Before you begin, gather these essential tools:
- Metal Measuring Tape: Cloth tapes can stretch and lead to inaccurate measurements.
- Pencil and Paper: To record your measurements.
- Step Ladder (if needed): For high windows.

Understanding the Basics: Inside vs. Outside Mount
The first step is deciding whether you want an inside or outside mount:
Inside Mount
An inside mount means the blinds are installed within the window frame. This creates a clean, recessed look. Here’s how to measure:
- Width: Measure the inside width of the window frame at the top, middle, and bottom. Use the smallest measurement.
- Height: Measure the inside height of the window frame from the top to the sill at the left, middle, and right. Use the smallest measurement.
- Depth: Ensure you have enough window depth for an inside mount. Check the manufacturer’s specifications.
Outside Mount
An outside mount means the blinds are installed outside the window frame, covering the entire window and potentially the surrounding wall. This is ideal for windows with shallow frames or when you want to block more light. Here’s how to measure:
- Width: Measure the width you want the blinds to cover. Add at least 2-4 inches to each side of the window frame.
- Height: Measure the height you want the blinds to cover. Add at least 2-4 inches to the top of the window frame.

Step-by-Step Measuring Guide
Let’s break down the measuring process further:
1. Measure the Width
For an inside mount, measure the width at the top, middle, and bottom of the window opening. Use the smallest measurement. For an outside mount, measure the desired width and add the necessary overlap.
2. Measure the Height
For an inside mount, measure the height at the left, middle, and right of the window opening. Use the smallest measurement. For an outside mount, measure the desired height and add the necessary overlap.
3. Record Your Measurements
Write down your measurements carefully, noting which window they correspond to. Always specify width first, then height (width x height).
4. Double-Check Your Measurements

It’s always a good idea to double-check your measurements to avoid errors. Measure twice, order once!
Tips and Tricks for Perfect Measurements
- Measure Each Window Individually: Windows can vary in size, even in the same room.
- Round to the Nearest 1/8 Inch: Most blind manufacturers work with these increments.
- Consider Obstacles: Note any obstructions like window cranks or handles that might affect the fit.
- Consult the Manufacturer’s Instructions: Always refer to the specific instructions provided by the blind manufacturer.
Choosing the Right Blinds
Once you have your measurements, you can confidently choose the right blinds for your windows. Consider factors like material, style, and light control.
By following these steps, you can ensure a perfect fit for your window blinds and enjoy a beautifully transformed space.