Bias Tape Yield Reference
What a square of fabric actually turns into once it goes through the continuous-bias method: the tape length yielded, the finished double-fold width, and how much edge that tape will bind — every figure computed by the same functions behind the bias tape calculator.
Square size & strip width → yield
| Fabric square | Cut strip width | Continuous-bias length yielded | Finished width (double-fold) | Edge it binds |
|---|---|---|---|---|
| 18in × 18in | 1.5in | 194in | 3/8in | 183in |
| 18in × 18in | 2in | 145in | 1/2in | 137in |
| 18in × 18in | 2.5in | 116in | 5/8in | 109in |
| 24in × 24in | 1.5in | 345in | 3/8in | 327in |
| 24in × 24in | 2in | 259in | 1/2in | 245in |
| 24in × 24in | 2.5in | 207in | 5/8in | 196in |
| 30in × 30in | 1.5in | 540in | 3/8in | 513in |
| 30in × 30in | 2in | 405in | 1/2in | 384in |
| 30in × 30in | 2.5in | 324in | 5/8in | 307in |
| 36in × 36in | 1.5in | 777in | 3/8in | 739in |
| 36in × 36in | 2in | 583in | 1/2in | 554in |
| 36in × 36in | 2.5in | 466in | 5/8in | 442in |
| 45in × 45in | 1.5in | 1215in | 3/8in | 1156in |
| 45in × 45in | 2in | 911in | 1/2in | 866in |
| 45in × 45in | 2.5in | 729in | 5/8in | 693in |
Yield assumes the calculator’s default 10% waste allowance; binding length assumes its default 5% ease and 1in join allowance. Both figures round in the direction that won’t leave you short — yield rounds down, edge-bound rounds down again on top of that.
How each column is derived
The continuous-bias method turns one square of fabric into a single long spiral of tape: cut the square diagonally, rejoin the two triangles offset by one strip-width into a parallelogram, sew the long edges into a tube, and cut around that tube in one uninterrupted spiral. The length that comes off is approximately the square’s area divided by the strip width, less a waste allowance for the diagonal seam and the trimmed ends at either end of the spiral — exactly what biasLengthFromSquare()computes. A 36in square cut into 2in strips, for instance, yields 583in of tape once that 10% waste is subtracted from the raw 1,296in² of area.
The finished-width column divides the same strip width by 4, because double-fold bias tape is folded to the center from both raw edges and then folded again — two folds consume roughly three quarters of the cut width, leaving one quarter as the finished, visible tape. A 2in strip becomes 1/2in finished tape; a 1.5in strip becomes 3/8in.
The edge-bound column runs the calculator’s binding-length math in reverse. Going forward, the calculator adds 5% ease (so the tape can wrap a curve or a corner without pulling tight) and a 1in join allowance (to overlap and finish the two ends) on top of an edge’s raw length. Going backward from a length of tape you already have, this table subtracts that same 1in and divides by the same 1.05 — then floors the result, so the figure shown is always a length that tape will genuinely cover, never an optimistic rounding-up.
Frequently Asked Questions
Where do the numbers in this table come from?
Every yield figure is computed by the same biasLengthFromSquare() function behind the bias tape calculator's "tape obtainable from a square you already have" section — this page doesn't maintain a separate copy of the math. It applies the calculator's default 10% waste allowance for the tube seam and the trimmed ends at the spiral's two loose ends.
Why does the table only show double-fold finished width?
Double-fold bias tape (folded to the center twice) is the more common finished product, and its conversion is a clean divide-by-4. Single-fold tape (one fold, no second turn-under) needs roughly half the strip width plus a small seam allowance instead — see the calculator's single-fold note — so it isn't a clean multiple of these same strip widths and is left out of this table to avoid implying a false precision.
What does "edge this binds" actually mean?
It's the longest edge you could realistically bind with the tape a row yields, after backing out the same 5% ease and 1in join allowance the calculator's binding-length section adds when going the other direction (edge length → tape needed). It's a floor, not a promise — an estimate of usable capacity, the same conservative direction the calculator's own yield figure already takes.
My square isn't one of these sizes. What do I do?
Use the bias tape calculator directly — enter your actual square side and strip width in its third section ("tape obtainable from a square you already have") for an exact figure. This table exists for the handful of sizes people cut most often, not as a substitute for the calculator.
Educational reference only. Real yields vary with cutting accuracy, seam width, and fabric grain — cut a little extra rather than exactly to a table figure.
Use it with
- Bias Tape Length Calculator— run any square size or strip width not shown here, or work forward from an edge length to the binding you need to cut.
- The Continuous Bias Tape Method, Step by Step — the full cutting-and-sewing procedure this table’s yield figures come from.
- How Much Bias Tape a Fabric Square Actually Yields — the guide version of this table, with the reasoning behind sizing a square for a real project.