Curtain fullness calculator
Enter the track width and the curtain type. The calculator gives you the fabric width you need straight away, based on the fullness ratio — with the standard side allowance included.
Measurements
Wave curtains run on a dedicated track with fixed spacing between the waves.
Result
Enter a track width to see the result.
Formula
Fabric width = Track width × Fullness
Add the side allowance (left + right), 5 cm per side as standard, to get the final net fabric width. Divide that width by the width of your fabric to find the number of widths you need.
What is curtain fullness?
Fullness tells you how many times the track width you need in fabric. A fullness of 2.0 (often written as 2×) means a 300 cm track takes 600 cm of fabric, before side allowances and seams. The higher the fullness, the fuller the curtain hangs — and the more fabric goes into the quote. Fullness always applies to the width, never to the drop.
Fullness by curtain type
| Curtain type | Fullness | Notes |
|---|---|---|
| Wave curtain (60 mm wave) | 2.0 | Standard on most wave tracks |
| Wave curtain (80 mm wave) | 2.2 | Deeper waves, a fuller drape |
| Wave curtain (100 mm wave) | 2.4 | Luxury finish, more fabric |
| Pencil pleat | 2.0 – 2.5 | Narrow, tight gathers |
| Double pleat | 2.0 – 2.2 | Two folds per pleat |
| Triple pleat | 2.5 – 3.0 | A richer, fuller look |
| Goblet pleat | 2.2 – 2.5 | Wide cup shape |
| Sheer, stretched flat | 1.5 – 1.8 | Fabric pulls flat between the clips |
| Sheer, lightly gathered | 2.0 – 2.5 | Airy, translucent effect |
| Roman blind / roller blind | 1.0 | Made up flat, no pleats |
Rules of thumb from practice. For wave systems, the track manufacturer's technical data sheet takes precedence: manufacturers such as Silent Gliss and Integra give the recommended fullness for each profile.
How to use the result
The calculator gives the net fabric width: track width × fullness, plus the standard side allowance of 5 cm per side. Divide that width by the width of your fabric to find the number of widths, and always round up. Then add a seam allowance for each width — allow 2 to 3 cm per seam — and, for a patterned fabric, the pattern repeat as well, so the pattern matches across the widths.
Two common mistakes: working from the window width instead of the track width (the track usually extends 15 to 20 cm beyond the window on each side), and applying fullness to the drop. The length comes from the finished drop plus the hem, the heading and, where needed, the pattern repeat.
Frequently asked questions
What is the standard fullness for curtains?
There is no universal standard. For wave curtains, 2.0 is the most common starting point; for traditional pleated curtains the fullness is usually between 2.0 and 2.5, depending on the heading. For Roman blinds the fullness is 1.0.
Do I apply fullness to the window width or the track width?
Always to the track width. The track usually extends 15 to 20 cm beyond the window on each side, so the curtain blocks the light and can be drawn clear of the glass. Working from the window width leaves you short of fabric every time.
Does fullness apply to the drop as well?
No, fullness only applies to the width. The fabric length comes from the drop plus an allowance for the hem and the heading, and for a patterned fabric also for the pattern repeat.
How much side allowance should I add?
5 cm per side as standard, so the curtain meets neatly when closed. This calculator already includes that allowance in the fabric width it gives you.
Fabric usage calculator
Work out the total fabric usage, including pattern repeat, seams and hems.
Let Gordana work it out for you
In Gordana you enter the measurements once — it works out the fabric usage, price and quote automatically.
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