Introduction
At Workroom by Design, we understand that both interior designers and homeowners seek stylish, functional window treatments that perfectly fit their space. Measuring your windows accurately is essential when selecting new blinds, whether for a client or personal use. This guide provides expert advice on measuring for both inside and outside mount blinds, ensuring an impeccable fit every time.
Understanding Mounting Options

Outside Mount Blinds
Outside mount blinds extend beyond the window frame, providing enhanced light control and making windows appear larger. These blinds are suitable when the window depth is insufficient for an inside mount or when maximum privacy and coverage are desired. Designers often use outside mounts to create dramatic visual effects or to complement other window treatments.

Inside Mount Blinds
Inside mount blinds fit snugly within the window frame, offering a sleek, built-in appearance. These are ideal for interior designers looking to create a minimalist, custom look with minimal obstruction to the window trim. However, they require precise measurements, as even minor miscalculations can affect the installation.
Tools Needed for Measuring Blinds
To ensure precise measurements, gather the following tools:
- Steel measuring tape (for accuracy)
- Notepad and pencil (to record dimensions)
- Level (optional, for ensuring even installation)
- Step stool (for higher windows)
Step-by-Step Guide to Measuring for Window Blinds
Measuring for Inside Mount Blinds
- Measure the Width: Measure across the top, middle, and bottom of the window. Use the narrowest measurement to ensure a proper fit.
- Measure the Height: Measure from the top to the bottom in three places—left, center, and right. Use the longest measurement.
- Measure the Depth: Check if your window frame meets the depth requirement for inside mount blinds. If not, an outside mount may be required.

Measuring for Outside Mount Blinds
- Measure the Width: Measure the total width of the window, including the frame. Add at least 2-3 inches on each side for better coverage and light control.
- Measure the Height: Measure from the top of the window to the desired blind length. Adding 3-4 inches above the window improves mounting stability.
- Consider Additional Allowances: Ensure space for mounting brackets and headrails, which typically require 2-3 inches.

Common Measurement Mistakes to Avoid
- Rounding measurements incorrectly – Always round to the nearest 1/8 inch for precision.
- Using old blinds’ measurements – Always measure the window itself to avoid size discrepancies.
- Measuring only one window – Even seemingly identical windows can have slight variations.
- Ignoring obstructions – Consider window handles, molding, or locks that might interfere with the blind installation.
Special Considerations for Custom Blinds
If you’re an interior designer selecting custom blinds, verifying product specifications is essential. Different styles may require different measurements, and some manufacturers automatically adjust sizes for a perfect fit. Check all details before placing an order.
Conclusion
At Workroom by Design, we believe that accurate measurements are key to achieving stylish, functional window treatments. Whether you’re a professional interior designer working on a project or a homeowner looking to enhance your space, following these expert tips will ensure your blinds and curtains fit perfectly. If you’re unsure, consider professional measuring services for added confidence.
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