| Use case | Size (L×W×T) | Qty | Boxing | Repeat | Waste | Typical yardage |
|---|---|---|---|---|---|---|
| Garden chair seat | 20×20×4 in | 2 | Yes | 0 in | 10% | ~2.5–3.5 yd |
| Bench cushion | 48×18×3 in | 1 | Yes | 0 in | 12% | ~2.0–2.8 yd |
| Patterned patio set | 22×22×5 in | 4 | Yes | 8 in | 20% | ~8.0–11.0 yd |
- Panel cut size: PanelWidth = CushionWidth + 2×Seam, PanelLength = CushionLength + 2×Seam. Two panels per cushion (top and bottom).
- Boxing length: Perimeter = 2×(L + W) + JoinAllowance + ZipperMargin. Boxing strip width is T + 2×Seam.
- Layout across fabric: Across = floor(FabricWidth / PieceWidth), Rows = ceil(PieceCount / Across), CutLength = Rows × PieceLength.
- Repeat matching (optional): AdjustedLength = ceil(CutLength / Repeat) × Repeat applied per cut row.
- Waste factor: TotalCut = BaseCut × (1 + Waste%), then Yards = TotalCut / 36.
- Measure cushion length, width, and thickness on the finished foam.
- Select your unit, then enter the number of cushions you need.
- Set fabric width from the bolt label (commonly 54 inches).
- Choose a seam allowance you actually sew with.
- If your fabric has a repeat, enter it and enable pattern matching.
- Pick a waste factor based on print size and your cutting skill.
- Press Calculate to see yardage above the form, then export.
Garden cushions fail early when covers are cut too tight or seams sit on high-stress edges. This calculator converts finished foam dimensions into practical cut sizes by adding seam allowance on every edge, then estimating yardage by how pieces nest across fabric width. A common patio seat is 20×20×4 inches; two cushions with boxing and 10% waste often need about 3 yards.
Most outdoor upholstery bolts are 54 or 60 inches wide. The calculator tests panel orientation and chooses the option that uses fewer “rows” along the length of the fabric. Even a small change in panel width can reduce pieces-per-row from two to one, doubling the length required. If panel width is close to half the fabric width, rotation can improve yield.
Boxing adds a perimeter strip that scales with 2×(length+width). Thickness drives strip width, so a 5-inch deep cushion consumes more across-fabric capacity than a 3-inch cushion. Adding a zipper typically needs extra handling room near the join, so the estimate includes a small margin. For outdoor projects, 0.5-inch seams are common, while heavier fabrics may benefit from 0.625 inches to preserve stitch strength.
Solids and textures can often stay near 5–10% waste. Large stripes, plaids, or motifs can push waste to 15–20%, especially when matching across multiple cushions. When pattern matching is enabled, the calculator rounds each cut row up to the next repeat multiple, reflecting how real cutting tables work. If your repeat is 8 inches, a 22-inch cut row may become 24 inches, increasing yardage predictably.
For sun and moisture exposure, prioritize solution-dyed acrylic or performance polyester, and pair it with UV-rated thread. Round up to the nearest quarter-yard for retail purchasing and keep remnants for piping, ties, or future repairs. Always confirm whether your fabric has a “railroaded” weave, because orientation can change how panels should be placed.
1) Why does thickness affect yardage so much?
Thickness increases boxing strip width, which reduces how many strips fit across the fabric. Fewer strips across means more length is needed to reach the cushion perimeter.
2) Should I enable pattern matching for small textures?
Usually no. Small textures and heathers rarely need alignment. Keep matching off and use 5–10% waste unless you have a strong directional look you must align.
3) What fabric width should I enter if my bolt is 58 inches?
Enter the usable width, not the selvage-to-selvage measurement. If the printable area is 56 inches, use 56 to avoid underestimating yardage.
4) Does this include piping or ties?
No. Add extra fabric for piping, welting, or ties. A practical add-on is 0.25–0.75 yards depending on how many cushions and the trim style.
5) Why does rotating panels change results?
Rotation changes the panel width across the fabric. If the new width allows more panels per row, the calculator reduces rows and total cut length.
6) What waste percentage is safest for beginners?
Start with 12–15% for solids and 15–20% for prints. This covers alignment errors, re-cuts, and small mistakes without dramatically overspending.