Use a metal tape measure for the most accurate measurements.

1. Measure the width of the inner recess at three points: top, middle, and bottom. Record the smallest measurement.
2. Measure the height (or drop) at three points: left, middle, and right. Record the smallest measurement.
3. Check for any obstructions like window handles to ensure enough space for the blind to operate smoothly.
4. Recheck your measurements to ensure accuracy, as precise measurements make it easier for us to provide an accurate quote.