How to Measure for Curtains
Start with the window measurements that matter before choosing a rod or panel length.
Curtain measurement tool
Curtain Size Calculator
Enter your window measurements and get a practical curtain width, panel count, length, rod width, and mounting height recommendation before you buy.
How the Calculator Works
Most curtains look better when their combined fabric width is wider than the window. A standard starting point is about 2 times the window width, while sheer or decorative curtains may use more fullness and simple coverage can use less.
Outside mount curtains usually need extra rod width on both sides of the window and a few inches of mounting height above the frame. Inside mount curtains stay closer to the measured opening.
Popular Curtain Guides
How Wide Should Curtains Be?
Understand fullness multipliers and why narrow curtains often look unfinished.
How Many Curtain Panels Do I Need?
Use panel width and total curtain width to estimate how many panels to buy.