Curtain Size Calculator
Get perfectly sized curtains every time. Enter your window measurements, choose your preferred fullness and length style, and this calculator will tell you the exact panel dimensions and how much fabric you need to buy.
Properly sized curtains make a room look polished and intentional. The key measurements are:
- Width: Multiply your window or rod width by the fullness factor (1.5x-2.5x) to get the total curtain width, then divide by the number of panels.
- Length: Measure from the rod to your desired endpoint. Floor-length curtains should just kiss the floor. Puddle curtains add 2 extra inches for a luxurious pooling effect.
- Fabric: Add 8 inches to the cut length for hems (4 inches top and bottom) and 4 inches to width for side hems.
A fullness of 2x is the most common choice and creates elegant, full gathers. For sheer fabrics, go with 2.5x for proper coverage. For a more tailored, flat look, 1.5x works well with heavier fabrics like velvet or blackout material.
Pro tip: Mount your curtain rod 4-6 inches above the window frame and extend it 3-8 inches beyond each side. This makes windows appear larger and lets in more light when curtains are open.