{
  "id": "quilt-binding",
  "version": "3892e50c25c3",
  "status": "published",
  "name": "Quilt Binding Calculator",
  "question": "How much quilt binding do I need?",
  "summary": "Works out the length of binding a quilt needs, how many strips to cut across the fabric width, and how much fabric to buy, rounded up to the next 1/8 yard.",
  "category": "everyday-life",
  "subcategory": "clothing",
  "url": "https://www.acalculator.org/everyday-life/quilt-binding-calculator",
  "markdown": "https://www.acalculator.org/everyday-life/quilt-binding-calculator.md",
  "kind": "function",
  "method": "Binding = 2 × (width + length) + extra; strips = ⌈binding ÷ fabric width⌉; fabric = strips × strip width, rounded up to 1/8 yd.",
  "assumptions": [
    "Strips are cut straight across the fabric width (not on the bias) and joined end to end.",
    "The extra length covers the joins, the corners and the two ends.",
    "The length is rounded up to the next 1/8 yard (or 0.1 m), as fabric is usually cut."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "w": {
        "title": "Quilt width",
        "description": "The finished width of the quilt.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.0254,
        "maximum": 12.7
      },
      "l": {
        "title": "Quilt length",
        "description": "The finished length of the quilt.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.0254,
        "maximum": 12.7
      },
      "sw": {
        "title": "Strip width",
        "description": "How wide you cut each binding strip; 2 1/2 in is common for double-fold binding.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.0127,
        "maximum": 0.254
      },
      "fw": {
        "title": "Fabric width",
        "description": "The usable width of the fabric the strips are cut across, about 42 in for quilting cotton.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0.127,
        "maximum": 5.08
      },
      "x": {
        "title": "Extra length",
        "description": "Added to the perimeter for joining the strips, the corners and the ends; 10 in is common.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "length",
        "minimum": 0,
        "maximum": 5.08
      }
    }
  },
  "outputs": {
    "buy": {
      "label": "Binding fabric to buy",
      "description": "Strips × strip width, rounded up to the next 1/8 yard, and to the next 0.1 meter.",
      "format": "text"
    },
    "strips": {
      "label": "Strips to cut",
      "description": "Binding length ÷ fabric width, rounded up.",
      "format": "integer"
    },
    "binding": {
      "label": "Binding length",
      "description": "2 × (width + length) + the extra length.",
      "format": "quantity",
      "unit": "in"
    },
    "perimeter": {
      "label": "Quilt perimeter",
      "description": "2 × (width + length).",
      "format": "quantity",
      "unit": "in"
    },
    "fabricLength": {
      "label": "Fabric length",
      "description": "Strips × strip width, before rounding.",
      "format": "quantity",
      "unit": "in"
    },
    "yards": {
      "label": "Yards to buy",
      "description": "Rounded up to the next 1/8 yard.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "w": 1.524,
      "l": 2.032,
      "sw": 0.0635,
      "fw": 1.0668,
      "x": 0.254
    },
    "outputs": {
      "buy": "1/2 yd (0.5 m)",
      "strips": 7,
      "binding": 7.366,
      "perimeter": 7.112,
      "fabricLength": 0.4445,
      "yards": 0.5
    },
    "text": "A 60 in × 80 in quilt needs 290 in of binding: cut 7 strips and buy 1/2 yd (0.5 m)."
  },
  "examples": [
    {
      "given": {
        "w": 1.524,
        "l": 2.032,
        "sw": 0.0635,
        "fw": 1.0668,
        "x": 0.254
      },
      "expect": {
        "binding": 7.366,
        "strips": 7,
        "fabricLength": 0.4445,
        "yards": 0.5,
        "buy": "1/2 yd (0.5 m)"
      },
      "source": "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement (1 yard = 36 inches; 1 inch = 2.54 centimeters exactly), https://www.nist.gov/document/2026-nist-handbook-44-appendix-c (retrieved 2026-10-03); hand calculation in content.mdx: 2 × 140 + 10 = 290 in; 290 ÷ 42 = 6.9, so 7 strips × 2.5 = 17.5 in, up to 1/2 yd"
    },
    {
      "given": {
        "w": 2.286,
        "l": 2.7432,
        "sw": 0.05715,
        "fw": 1.016,
        "x": 0.30479999999999996
      },
      "expect": {
        "binding": 10.363199999999999,
        "strips": 11,
        "fabricLength": 0.6286499999999999,
        "yards": 0.75,
        "buy": "3/4 yd (0.7 m)"
      },
      "source": "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement (1 yard = 36 inches; 1 inch = 2.54 centimeters exactly), https://www.nist.gov/document/2026-nist-handbook-44-appendix-c (retrieved 2026-10-03); hand calculation in content.mdx: 2 × 198 + 12 = 408 in; 408 ÷ 40 = 10.2, so 11 strips × 2.25 = 24.75 in = 0.6875 yd, up to 3/4 yd"
    },
    {
      "given": {
        "w": 1,
        "l": 1.2,
        "sw": 0.065,
        "fw": 1.1,
        "x": 0.25
      },
      "expect": {
        "strips": 5,
        "buy": "3/8 yd (0.4 m)"
      },
      "source": "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement (1 yard = 36 inches; 1 inch = 2.54 centimeters exactly), https://www.nist.gov/document/2026-nist-handbook-44-appendix-c (retrieved 2026-10-03); hand calculation in content.mdx: 440 + 25 = 465 cm; 465 ÷ 110 = 4.2, so 5 strips × 6.5 = 32.5 cm, up to 0.4 m; 0.355 yd, up to 3/8 yd"
    }
  ],
  "sources": [
    "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement (1 yard = 36 inches; 1 inch = 2.54 centimeters exactly). https://www.nist.gov/document/2026-nist-handbook-44-appendix-c (retrieved 2026-10-03)"
  ],
  "related": [
    "quilt-backing",
    "fabric",
    "yardage"
  ],
  "changelog": []
}