THE NUMBERS, EXPLAINED
How to use this calculator.
Cut straight strips across the usable fabric width. Enter the actual loss per join for your joining method and an extra allowance for corners and closing the binding. This is not a continuous bias cutting layout.
Start with your inputs
Enter quilt perimeter (cm), cut binding strip width (cm), usable fabric width (cm), length lost at each strip join (cm), extra length for corners and final closure (cm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Quilt perimeter (cm) | 600 |
| Cut binding strip width (cm) | 6 |
| Usable fabric width (cm) | 110 |
| Length lost at each strip join (cm) | 6 |
| Extra length for corners and final closure (cm) | 30 |
A worked example
With the example inputs above, binding length needed (cm) is 630. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Binding length needed (cm) | 630 |
| Strip count | 6 |
| Fabric length (cm) | 36 |
| Joined binding available (cm) | 630 |
How this is calculated
Binding length needed (cm)
Add perimeter and the extra length allowance.
Strip count
Choose the smallest integer n with n × usable width − (n−1) × join loss at least the needed length.
Fabric length (cm)
Multiply strip count by cut strip width.
Joined binding available (cm)
Add all strip lengths and subtract loss at every join.
Symbols and units
- a
- Quilt perimeter (cm)
- b
- Cut binding strip width (cm)
- c
- Usable fabric width (cm)
- d
- Length lost at each strip join (cm)
- e
- Extra length for corners and final closure (cm)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
Cut straight strips across the usable fabric width. Enter the actual loss per join for your joining method and an extra allowance for corners and closing the binding. This is not a continuous bias cutting layout.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Binding length needed (cm); Strip count; Fabric length (cm); Joined binding available (cm). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Cut straight strips across the usable fabric width. Enter the actual loss per join for your joining method and an extra allowance for corners and closing the binding. This is not a continuous bias cutting layout.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
Janome: joining binding strips ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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