Inside Mount: Blinds fit inside the window frame for a clean, streamlined look. This is ideal for windows with deep recesses.
Outside Mount: Blinds are mounted outside the window frame, either on the wall or trim. This style provides full coverage, making it perfect for windows with shallow frames or if you want to block out more light.

Width: Measure inside the window frame at three points: the top, middle, and bottom. Use the narrowest measurement to ensure the blinds fit inside the frame perfectly.

Height: Measure the height in three places: left, center, and right. Use the longest measurement to make sure the blinds cover the entire window.
Depth: Check the depth of your window frame. Most inside-mount blinds require at least 3 inches of depth to fit properly. Measure at three points along the frame for consistency.

Width: Measure the total width from one edge of the window frame to the other. If you want extra coverage, add 3-4 inches to the width. This ensures the blinds extend beyond the window for better light blocking.
Height: Measure the height from the top of the window frame to the bottom. Add about 3 inches above the frame to account for mounting brackets and proper positioning of the blinds and 2 inches below the frame to minimize light seeping through.
Protrusions & Brackets: Make sure to measure around any window handles or obstructions and include the space needed for the mounting brackets.

For arched or angled windows, you may need to take additional measurements at various points to account for the shape. It's best to consult a specialist for these types of installations.
For bay windows or skylights, measure each section individually and consider using custom blinds designed specifically for these shapes.

Always double-check your measurements to ensure accuracy.
For the most precise fit, order blinds based on your exact measurements rather than estimating.
When recording measurements, list them as width x height (W x H).