About the Curtain Size Calculator
Curtain width and drop from your window and pole, including the fullness ratio and fabric needed.
Also known as: curtain fabric calculator, curtain width calculator, how much curtain fabric, curtain measurements.
How to use this calculator
- Enter pole or track width, required drop, heading fullness, curtains and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
fabric = ceil(pole width × fullness ÷ roll width) × cut drop
Worked example
Using the values pre-filled in the calculator above:
- Pole or track width = 1,500 mm
- Required drop = 1,800 mm
- Heading fullness: Pencil pleat (2×)
- Curtains: A pair
- Hem and heading allowance = 250 mm
- Fabric roll width = 1,370 mm
- Pattern repeat = 0 mm
the calculator returns:
- Fabric required: 6.15 m
- Finished width per curtain: 1,500 mm
- Total flat width: 3,000 mm
- Fabric widths needed: 3