Curtain Calculator: Width, Length & Fullness
Work out the curtain width, length and fullness for any window. Enter the rod width and the drop, and the calculator gives you the fabric width, the length, and the number of panels to buy.
How this calculator works
Total fabric width is the rod width multiplied by the fullness, usually 1.5 times for a light fabric and 2 times for a full, formal look. Divide by two for a pair of panels. Length is the distance from the rod to the floor or sill. The rod should be 6 to 8 inches above the window and 6 to 8 inches beyond each side, so the window looks larger.
Related guide: How to Choose Curtains: Size, Fabric and Hanging Guide
How to use this calculator
- Measure your room carefully — length, width and height — and note doors and windows.
- Enter the numbers above and check the result.
- Round up to the next pack or tin size, and add about 10% for waste and touch-ups.
- Read the full guide: How to choose curtains — it explains the measurements, the mistakes to avoid and the FAQs.
Frequently asked questions
How wide should curtains be?
1.5 to 2 times the rod width, for a full, gathered look. A fullness of 1.5 suits a light fabric; a fullness of 2 suits a heavy fabric or a formal room.
How long should curtains be?
Floor-length curtains should just touch the floor. Sill-length curtains should end at the windowsill, and they suit kitchens and bathrooms.
How high should I hang curtains?
6 to 8 inches above the top of the window frame, and 6 to 8 inches beyond each side, so the window looks larger and the room looks taller.
How many curtain panels do I need?
Two panels for most windows, one on each side. Each panel should be at least half the total fabric width.