🪟 Blind Size Calculator
Enter your window’s measured width and height and choose inside or outside mount to get the correct blind size to order.
What this calculator does
The Blind Size Calculator converts your measured window dimensions into the correct blind size to order, adjusting for whether the blind will mount inside the window frame or outside over the frame.
How the calculation works
For an inside mount, a small clearance of about a quarter inch is subtracted from the measured width so the blind can rotate and operate freely inside the frame, while the height is kept as measured. For an outside mount, extra width and height (commonly about 1.5 inches per side and a similar allowance top and bottom) are added so the blind fully overlaps the frame and blocks more light.
This tool gives a general estimate for shopping purposes. Always double-check with the specific blind manufacturer’s sizing guidelines, since exact clearance recommendations vary by product.