Curtain Fabric Calculator
Sewing your own curtains? Enter the rod length, curtain length and your fabric's width to get how many yards (or meters) to buy, how many widths to cut, and each cut length, including hems, header and pattern repeat.
How curtain yardage is calculated
- Finished width: rod length × fullness, divided by the number of panels. A 68 in rod at 2× is 136 in, or 68 in per panel for a pair.
- Cut width: add the side hems (3 in each side), then work out how many fabric widths to sew together, in half widths for a pair. Each join uses about 1 in of fabric.
- Cut length: finished length + header allowance + bottom hem. For a patterned fabric, round up to a whole number of pattern repeats so every panel matches.
- Total: number of cuts × cut length (+ one repeat for patterns), divided by 36 for yards. Buy a little extra for shrinkage if the fabric isn't pre-washed.
Typical allowances
| Part | Allowance | Why |
|---|---|---|
| Bottom hem | 8 in (double 4 in) | Weight helps curtains hang straight |
| Side hems | 3 in per side (double 1½ in) | Clean edges that don't curl |
| Grommet or pinch pleat header | 8 in | Double 4 in fold, often with buckram |
| Rod pocket | About 7 in | Pocket for the rod plus a small ruffle and turn-under |
| Flat top for rings or clips | 4 in | Double 2 in fold |
| Joining widths | ½ in per seam side | 1 in of width lost per join |
Not sure of the finished size yet? Start with the curtain size calculator, then bring the rod length and curtain length here. For bay windows, use the bay window curtain calculator and work out each section separately.
Frequently asked questions
How many yards of fabric do I need for curtains?
For a standard pair of floor-length curtains (84 inches) on a 48-inch window, with 2× fullness and 54-inch-wide fabric, you need three cuts of 100 inches (each panel is 1½ widths): about 8½ yards. The calculator works it out from your rod length, curtain length, header and fabric width.
How much extra fabric do I need for hems?
Allow about 8 inches at the bottom for a double 4-inch hem, 4 to 8 inches at the top depending on the header (8 inches for grommets or pinch pleats), and 3 inches on each side for double 1½-inch side hems.
What is a pattern repeat?
The distance before a printed pattern starts again, printed on the selvage or the product page. Each cut must start at the same point in the pattern so the panels match, so every cut length is rounded up to a whole number of repeats, plus one extra repeat to line up the first cut.
Do I need lining fabric?
Lining protects the curtain fabric from sun, helps it hang better and adds privacy; blackout lining blocks light. Lining is usually cut about the same width as the curtain fabric and a few inches shorter, so you need roughly the same yardage again, minus the header allowance.