Window Blinds Size Calculator
Blind Measurements
Important Measurement Notes
Inside Mount: Blinds fit within the window frame. Requires adequate depth (typically 2-3 inches minimum).
Outside Mount: Blinds are mounted on the wall or window trim, extending beyond the window opening for better light control.
Measurement Guidelines
Always measure your windows at three points: top, middle, and bottom for width; left, center, and right for height. Use the smallest measurement to ensure proper fit.
For inside mounts, deduct 1/4 to 1/2 inch from your measurements to allow for easy operation and mounting hardware.
Blind Type Considerations
Horizontal Blinds: Ideal for most windows, available in various slat sizes from 1/2″ to 2″.
Vertical Blinds: Perfect for sliding doors and large windows, typically 3.5″ wide vanes.
Roller Blinds: Sleek and modern, require minimal mounting space.
Installation Requirements
Inside mount requires minimum 2″ depth for most blinds, 3″ for some cellular shades.
Outside mount should extend 2-4″ beyond window opening on each side for optimal light blocking.
Consider obstacles like window handles, locks, or protruding trim when measuring.
Common Sizing Mistakes
Not accounting for mounting hardware space in inside mount installations.
Forgetting to measure window depth before choosing inside mount option.
Not considering light gaps when sizing outside mount blinds.
Professional Measuring Tips
Use a steel measuring tape for accuracy. Measure to the nearest 1/8 inch. For inside mounts, check that the window opening is square by measuring diagonally from corner to corner – measurements should be equal. Consider the operating mechanism space when measuring – cordless blinds need less clearance than corded versions.