Measuring for Custom Blinds: A Homeowner's Step-by-Step Guide

Accurate measurements are essential for custom window treatments. When blinds and shades fit perfectly, they operate smoothly, look professional, and function as intended. Whether you're measuring yourself or preparing for a professional consultation, understanding the process ensures your custom treatments arrive correctly sized for flawless installation.

Gather the Right Tools

You'll need a steel measuring tape (not cloth, which stretches), a notebook for recording measurements, and a level to check if your window frame is square. Metal measuring tapes provide accuracy that cloth tapes cannot. A level reveals whether your windows are perfectly plumb—an important detail since some older homes have settled slightly over time.

Understand Inside Versus Outside Mount

Inside mounts fit within the window frame opening, creating a clean, tailored appearance. Outside mounts attach above and beyond the frame, covering the wall around the window. Inside mounts work best when your frame is at least one and a half inches deep. Outside mounts suit shallow frames or situations where you want maximum light blocking. This decision affects how you measure.

Measure Inside Mount Installations

For inside mounts, measure the width of your window opening at the top, middle, and bottom—use the smallest measurement. For depth, measure from the front of the frame inward at least one and a half inches to ensure clearance. Take height measurements at the left, center, and right sides of the opening, using the longest measurement. Record each in writing and double-check your work.

Measure Outside Mount Installations

Outside mounts extend coverage across the wall. Measure the desired width—typically extending six inches beyond the frame on each side—and note where you want the bottom of your treatment to fall. Some homeowners prefer treatments that extend to the baseboard, while others like them stopping at the windowsill. Clarify your preference before measuring.

Account for Architectural Details

Check for baseboards, crown molding, furniture, or other obstacles that might affect installation or operation. Note ceiling height if mounting high. Identify the window's orientation to discuss light-blocking requirements and UV exposure with your consultant.

Take Photos and Make Notes

Photograph each window from multiple angles and from different distances. Note the condition of frames, any quirks in how the window opens, and details you've noticed. Share these observations with your specialist to ensure all considerations are addressed.

Consider Professional Measurement

Many custom treatment specialists offer professional measuring services. An expert can identify installation challenges, discuss mounting options, and ensure measurements account for every detail. This eliminates guesswork and guarantees accuracy before production begins.

Trust Your Measurements

Precise measurements mean perfectly fitting treatments that operate smoothly and look intentional. Taking time with this step ensures your custom blinds arrive ready for flawless installation.