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THE FEUTEX TOOLKIT

Quilt Diagonal Backing Estimate

Estimate fabric length for a diagonal-spliced backing when the required width lies between one and two fabric widths.

Crafts workspace● Runs in your browser
01 Your input
02 Your result
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FormulaEstimated fabric length = length*fabric/(2*fabric-target)+allowance; Additional length above backing length = length*fabric/(2*fabric-target)+allowance-length

Made for real tasks

  • Estimate fabric length for a diagonal-spliced backing when the required width lies between one and two fabric widths.
  • Compare an alternative set of measurements without uploading personal data.
Explore step-by-step workflows →

Worked example

Inputs

Required backing length
180 cm
Required backing width
150 cm
Usable fabric width
110 cm
Extra length for seams and trim
10 cm

Expected results

Estimated fabric length
292.8571429 cm
Additional length above backing length
112.8571429 cm

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter required backing length, required backing width, usable fabric width, and extra length for seams and trim in the displayed units.
  2. Calculate and use each labeled result for quilt diagonal backing estimate. Compare the result with a measured sample before committing materials.

Try this example

{
  "length": 180,
  "target": 150,
  "fabric": 110,
  "allowance": 10
}

Accuracy and scope

Ideal diagonal splice geometry; very wide targets require excessive cloth. Verify the actual splice layout and seam allowance before cutting.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.