How Much Binding for a Twin Quilt?
Binding is the final strip that wraps the raw edges of your quilt, and on a twin it is the place where a small math error turns into a half-yard trip back to the fabric store. If you are figuring out how much binding for a twin quilt, the answer for a standard 70 by 90 inch twin is about 344 inches of binding — 9 strips at 2.5 inches wide, or roughly 0.75 yard of 42-inch fabric. Here is the full math, plus what changes when the top finishes a touch smaller or larger.
What Counts as a Twin Quilt
A standard twin mattress is 38 by 75 inches, and the most common twin quilt top finishes at 70 by 90 inches. Youth and bunk versions run closer to 66 by 89 inches, and a pillow-tuck twin can stretch to 74 by 94 inches. All three sizes are bed-sized projects, so the binding math is sensitive to even a couple of inches. The table below uses the 70 by 90 size, then extends to the variations so you can match your actual finished top.
Step 1: Find the Perimeter
Add the width and length, then multiply by two. For a 70" × 90" twin that is (70 + 90) × 2 = 320 inches of perimeter.
Step 2: Add the Joining Allowance
Add about 24 inches total (roughly 12 inches per side) for the diagonal join where the start and end strips meet and for easing the binding around mitered corners. So 320 + 24 = 344 inches of binding. That joining buffer is what keeps the math honest — without it, you can come up two or three inches short when the binding wraps the last corner.
Step 3: Count Strips and Yardage
Divide total binding length by usable fabric width (about 40 to 42 inches). 344 ÷ 42 ≈ 8.2, so you need 9 strips. At a 2.5-inch strip width that is 22.5 inches of fabric length, or 22.5 ÷ 42 ≈ 0.54 yard — round up and buy 0.75 yard so you have spare strip for a miscut or a scrappy binding leftover. If you cut 2.25-inch strips you still need 9, and the yardage drops only slightly, so 0.75 yard covers either width.
Twin Quilt Binding Reference Table
| Twin top size | Perimeter + 24" | 2.5" strips | Yardage to buy |
|---|---|---|---|
| 66×89 (bunk/youth) | 334" | 8 | 0.75 yd |
| 70×90 (standard) | 344" | 9 | 0.75 yd |
| 74×94 (pillow tuck) | 360" | 9 | 0.75 yd |
Notice that the standard twin and the pillow-tuck twin both need 9 strips, but the larger version squeezes in just inside the 0.75 yard mark. If you cut 2.75-inch strips for a chunky finish, the strip count stays at 9 but the yardage creeps up to 9 × 2.75 = 24.75 inches of length, or 24.75 ÷ 36 = 0.69 yard — still inside 0.75 yard. If you cut 3-inch strips, plan 1 yard to be safe.
Straight-Grain vs. Bias Binding
A rectangular twin has straight edges, so straight-grain binding cut across the width of fabric is all you need and uses the least yardage. Reserve bias binding for quilts with curved edges, where the stretch of a 45-degree cut helps the binding hug the curve. For a twin bed quilt, straight strips sewn with mitered corners give a crisp, durable finish that handles weekly laundering without warping out of shape.
Frequently Asked Questions
How much binding do I need for a 70 by 90 inch twin quilt?
A 70 by 90 inch twin quilt has a perimeter of 320 inches. Add about 24 inches for joining the ends and mitering the corners, giving roughly 344 inches of binding, or 9 strips cut 2.5 inches wide from 42-inch fabric (about 0.75 yard).
How many WOF strips do I need for a twin quilt?
For a 70 by 90 twin you need about 344 inches of binding. Each 42-inch width-of-fabric strip gives 42 inches, so 344 divided by 42 rounds up to 9 strips.
How wide should twin quilt binding be?
Most quilters cut 2.5-inch strips for double-fold binding, which finishes around 0.375 to 0.5 inch on the quilt edge. Use 2.25 inches for a slim binding or 3 inches for a chunky, modern look.
Can I use bias binding on a rectangular twin?
Straight-grain binding is enough for a rectangular twin because the edges are straight; bias binding is only necessary for curved quilt edges. Straight binding uses less fabric and is faster to cut.