Curtain Fabric Calculator 2026
Instantly calculate how much fabric you need for curtains. Enter your window width, drop, heading type, and fullness ratio — get exact metres, widths, and lining requirements.
Window & Curtain Specifications
Measure your track or pole, not the window frame
Measure the full length of your track or pole, including any overlap
From pole/track to desired hem position (floor, sill, or below sill)
Most windows use 2 panels (one per side)
Heading style determines the recommended fullness ratio
Pencil pleat: 2.0–2.5× recommended for a full gather
Standard upholstery/curtain fabric is typically 137cm (54″) or 150cm wide
Extra fabric at top for tape, folds, or rings (typically 10–20cm)
Double bottom hem: fold 8cm twice = 16cm total allowance
Enter 0 for plain or non-directional fabric. One repeat is added per width to allow pattern matching.
Fabric Requirements
Total metres, widths & lining quantities
Enter your window width, drop, and heading type above, then click Calculate Curtain Fabric to see your complete fabric shopping list.
Curtain Heading Types & Fullness
Standard fullness ratios and allowances for common curtain heading styles. Always add 10% for pattern matching and cutting wastage.
| Heading Type | Fullness Ratio | Heading Allow. | Hem Allow. | Notes |
|---|---|---|---|---|
| Pencil Pleat | 2.0–2.5× | 15–20cm | 16cm | Most popular; versatile & full |
| Eyelet / Grommet | 1.5–2.0× | 10–12cm | 16cm | Contemporary; neat ring-top look |
| Pinch Pleat | 2.0–2.5× | 20–25cm | 16cm | Traditional; tailored triple pleats |
| Tab Top | 1.5–2.0× | 10cm | 16cm | Casual style; fabric loops on pole |
| Goblet Pleat | 2.0–2.5× | 25–30cm | 16cm | Formal & elegant; stuffed cups |
| Wave / S-Fold | 2.0–2.2× | 12cm | 16cm | Modern; requires wave track system |
| Rod Pocket | 2.0–3.0× | 12–15cm | 16cm | Simple gathered sleeve over rod |
Curtain Fabric FAQ
Everything you need to know about calculating curtain fabric, from fullness ratios and pattern repeats to lining choices and drop allowances.
Multiply your track or pole width by your fullness ratio (typically 2 to 2.5 for pencil pleat). Divide by your fabric width to get the number of widths needed, then multiply by your cut drop (finished length plus hem and heading allowances). Add extra widths for pattern repeat matching if using patterned fabric.
Curtain fullness describes how much wider the fabric is compared to the track. A 2× ratio means the fabric is twice the track width. Pencil pleat and pinch pleat curtains typically use 2–2.5×. Eyelet curtains use 1.5–2×. Tab top and wave use around 2×. Higher fullness means a lusher, more gathered look but uses more fabric and costs more.
The cut drop equals the finished length plus heading and hem allowances. For a double hem, add 16cm (8cm folded twice). For the heading, add 10–20cm depending on your heading type. For floor-length curtains, measure from the pole or track to the floor and subtract 1–2cm so it just clears, or add 15–20cm for a fashionable puddle effect.
Add one full pattern repeat to every cut drop to allow patterns to align across all fabric widths. For example, with a 240cm cut drop and a 32cm pattern repeat, each width must be cut at 272cm. This wastage multiplies across several widths, so patterned fabric projects can need significantly more fabric than plain designs.
Lining improves insulation, light blocking, and how curtains hang. The lining fabric quantity mirrors the face fabric but is cut 5cm shorter. Blackout lining is identical in quantity to standard lining. Interlining adds a third soft layer between face and lining, cut to the same size as the lining, effectively doubling or tripling your total fabric order.
For sill-length curtains, measure from the pole or track to just below the window sill (add 1–2cm). For below-sill curtains, measure to roughly 15cm below the sill. For floor-length curtains, measure to the floor minus 1cm so they just clear. For a puddle effect, add 15–30cm below the floor line. Always measure from the eyelet, ring, or top of the track — not the window frame itself.