Input variables
| Variable | Meaning | Unit |
|---|---|---|
| length | Binding length needed | m |
| width | Cut strip width | mm |
| waste | Area allowance | % |
| fabric | Usable fabric width | cm |
Equations
Fabric area including allowance · m2
area = length*width/1000*(1+waste/100)
Approximate square side · cm
square = sqrt(area)*100
Length at usable fabric width · m
yardage = area/(fabric/100)
Notation
PI means π. ** means a power, sqrt means square root, and abs gives the absolute value. Trigonometric functions use radians. min and max select the smallest or largest argument.
ceil rounds upward, floor rounds downward, and round rounds to the nearest integer with halves toward positive infinity. roundup(value, step) rounds upward to the next multiple of the step; a zero step leaves the value unchanged.
Assumptions
- Enter cut width, before folds. Finished binding width is a different measurement.
- Area equivalence is an estimate; joins, diagonal layout and edge losses affect practical yield.
- A square gives an approximate continuous-bias starting size; round upward for cutting.
- Check whether your project uses single-fold, double-fold or quilt binding before choosing width.
Precision and verification
The tool uses ordinary double-precision numeric arithmetic. Output is displayed to at most four decimal places; measurement precision is usually much lower. Check the worked examples, your project’s specifications, and a real sample before committing material.