What the Curtain Fullness Calculator actually calculates
The tool divides combined flat panel width by track width. Ratios of at least 2.5 are labeled luxuriously full, at least 1.8 balanced, and lower values lightly gathered. These labels do not account for heading construction, fabric stiffness, returns, or center overlap; a ratio below one also means insufficient flat width to span the track.
The calculation path
Total flat panel width is divided by the track width to produce the fullness ratio.
Inputs that can change the answer
- Track width: Enter track width in m.
- Flat width per panel: Enter flat width per panel in m.
- Panels: Enter panels as a number; use the definition in the calculation method.
Checks that stay outside the formula
Use the fabric supplier’s recommended fullness for the selected heading style.
A practical order for entering the data
- Measure the usable track width in metres.
- Enter the flat finished width of one panel and the number of equal-width panels.
- Compare the achieved ratio with the fabric and heading supplier's recommended fullness.
Project walkthrough: Curtains: from window measurement to fabric order
Project walkthrough: Compare blinds and curtains from the same window measurements
Engine check using the prefilled sample
Window-treatment example: track width = 2.2 m, flat width per panel = 2.3 m and panels = 2. Replace the sample opening and fabric or hardware values with measurements taken for the mounting method you plan to use.
Results for these inputs
- Total flat width
- 4.60 m
- Achieved fullness
- 2.09 ×
- Fullness assessment
- Balanced fullness