Curtain Fabric Calculator
Work out exactly how much fabric your curtains need. Enter your pole width, finished length and header style — the calculator handles fullness ratio, number of panels, fabric width, pattern repeat and even lining yardage.
Calculate your curtain fabric
All math runs in your browser. Results update as you change inputs.
How the curtain fabric calculator works
Curtain yardage is a width problem and a length problem multiplied together. Here is the exact sequence the calculator runs:
Why fullness dominates the result
Fullness is how much wider the flat fabric is than the pole, so it can gather into folds. Skipping it is the #1 reason homemade curtains look flat and store-bought ones look full. Standard ratios:
| Header type | Fullness | 48 in pole needs (flat width) |
|---|---|---|
| Flat panel | 1.5× | 72 in |
| Grommet / eyelet / tab top | 2× | 96 in |
| Rod pocket, gathered | 2–2.5× | 96–120 in |
| Pinch pleat / pencil pleat | 2.5× | 120 in |
| Goblet pleat / wave | 3× | 144 in |
Worked example
A 48-inch pole, 63-inch finished length, pinch pleat curtains (2.5× fullness), a pair of panels, 54-inch fabric, no pattern repeat, 12 inches of allowances:
Add a 13-inch vertical pattern repeat and each cut becomes 78 inches (3 repeats), pushing the total to 312 inches ≈ 8⅝ yd — that is why repeat matters. If you use the same window with 110-inch wide sheer fabric instead, each panel is a single width: 2 cuts × 75 in = 150 in ≈ 4⅙ yd.
Buying tips that save fabric (and money)
Buy the width, not the length. Extra length is wasted if you mis-measured the width — you cannot add cuts after the dye lot changes. When in doubt, round up.
Check railroaded fabric. If the bolt label says "railroaded" and your curtain length is shorter than the fabric width, one piece can run top-to-bottom with no seams at all — sometimes halving your yardage.
One repeat extra, always. For pattern-matched pairs, buy one extra repeat beyond the calculator's number. It gives your workroom (or you) slack to align motifs at the panel edges where they meet.
Prewash first. Natural fibers can shrink 3–5%. Wash and press before cutting, or add 5–10% yardage if you plan to wash the finished curtains.
Frequently asked questions
How much fabric do I need for curtains?
Multiply your pole or track width by your fullness ratio (2× for grommets, 2.5× for pinch pleats), divide by the number of panels, then divide by the fabric width to get the number of fabric cuts. Multiply cuts by the cut length (finished length plus header and hem allowances, rounded up to the pattern repeat if matching). A 48-inch pole with 63-inch pinch-pleat curtains in 54-inch fabric needs about 8⅜ yards.
What fullness ratio should curtains have?
Flat panel: 1× to 1.5×. Grommet (eyelet) and tab-top: 2×. Rod pocket: 2× to 2.5×. Pinch pleat, pencil pleat and goblet pleat: 2.5×. For a luxurious wave, use up to 3×. Never go below 1.5× or the curtain will not gather properly.
How much extra fabric does pattern repeat add?
Every cut length must be rounded up to a whole multiple of the vertical pattern repeat so motifs match at panel edges and seams. With a 27-inch repeat and a 75-inch cut, each cut becomes 81 inches — about 8% more fabric. On two-panel curtains buy at least one extra repeat for matching flexibility.
How much lining fabric do I need for curtains?
Lining is cut to the same number of widths as the face fabric but usually 1–2 inches shorter in the hem, so lining yardage is roughly 90–95% of face yardage and pattern repeat does not apply. A standard 54-inch lining width fits most curtain widths.
Should curtains be one panel or a pair?
Windows up to about 36 inches wide often use a single panel; wider windows use a pair so each side stacks back evenly. The calculator handles both — choose 1 or 2 panels and the fullness is divided between them.