Bias Tape Yardage Calculator
Continuous bias binding turns a modest square of fabric into a long strip cut on the diagonal, which stretches smoothly around curves. The yield follows a clean rule: lay all the strips end to end and their area equals the fabric area, so total length is the fabric area divided by the cut strip width. This calculator works both directions: given a fabric size it tells you how much binding you get, and given a target length it tells you the size of square you need to cut. Enter the cut strip width you will actually use, since that is what the formula depends on.
Bias tape yield formula
Fabric area = width * length
Tape yield (in) = fabric area / strip width
Tape yield (yd) = yield in / 36
Fabric area needed = target length * strip width
Square side = sqrt(fabric area needed)
The continuous-bias method sews the fabric into a tube offset by one strip width and cuts a single spiral, achieving close to the theoretical area-over-width yield with little waste.
Bias binding context
- Total bias length equals fabric area divided by cut strip width: a geometric identity for the continuous method.
- Cut strip width is roughly twice the finished width for single fold and four times for double fold.
- Bias is cut at 45 degrees to the grain so the tape stretches around curves without puckering.
- Add 5 to 10 percent over your target length for joining seams and squaring up.
- One yard equals 36 inches; the inch is defined by the NIST Office of Weights and Measures.
Bias tape: frequently asked questions
How much bias tape does a square of fabric make?
The total length of continuous bias binding equals the area of the fabric divided by the cut strip width. A 36 by 36 inch square cut into 2 inch strips yields 36 times 36 divided by 2, which is 648 inches, or 18 yards before joins. This is the standard continuous-bias yield formula.
Why is it area divided by strip width?
If you laid all the strips end to end, their combined area would equal the fabric area. Each strip is the cut width wide, so total length is area divided by width. The continuous-bias method (sewing the fabric into a tube and cutting a spiral) achieves close to this theoretical yield with minimal waste.
What strip width should I cut?
The cut strip width is the finished tape width times a factor that depends on the fold style. Single-fold tape is cut about twice the finished width; double-fold about four times. Enter the cut width you will actually cut, because that is what the yield formula uses; finished width alone is not enough.
How much fabric do I need for a target length?
Rearrange the formula: required fabric area equals target length times strip width. The calculator takes the area as a square and reports the side of the square you would need, so you can buy or cut a piece that yields enough binding for your project.
Does this account for seams and waste?
The yield is the theoretical maximum for the continuous-bias method. Real output is slightly less because of the joining seams and squaring up. Add a margin of roughly 5 to 10 percent to your target length to be safe, especially for binding a quilt where running short mid-edge is a problem.
Official sources
- NIST: Units of length (inch and yard definitions).
- NIST: Office of Weights and Measures.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.