T-shirt quilt calculator
Twenty shirts at 14" blocks with 2" sashing makes a 4 x 5 grid finishing 62" x 78", and takes about 9 yards of fusible interfacing. Enter your shirt count below for your layout, quilt size, and the interfacing number everyone forgets to buy.
Your quilt
Why t-shirt quilts need interfacing
T-shirts are knit, and knit stretches in every direction, which is wonderful in a shirt and chaos on a cutting mat. Lightweight fusible interfacing (a woven or non-woven stabilizer ironed to the back of each shirt) freezes the knit so it cuts and sews like quilting cotton. The order of operations matters: rough-cut the shirt front larger than needed, fuse interfacing to the back, and only then trim to the final block size. Cutting first and fusing second is the classic regret.
Choosing a block size for t-shirt quilts
Measure your largest logo and add at least 2 inches of breathing room; that is your minimum finished block. Fourteen inches accommodates most adult shirt graphics, which is why it is the industry default. Mixing sizes is possible but turns the layout into a puzzle; the gentler path for a first t-shirt quilt is one block size, with smaller logos centered in the same block and enjoying their extra margin.
How many shirts make a good quilt?
| Shirts | Grid (14" blocks, 2" sashing) | Quilt center | About the size of |
|---|---|---|---|
| 9 | 3 x 3 | 46" x 46" | Baby play quilt |
| 12 | 3 x 4 | 46" x 62" | Lap quilt |
| 20 | 4 x 5 | 62" x 78" | Generous throw |
| 30 | 5 x 6 | 78" x 94" | Near queen |
A border from the border calculator grows any of these a size; many 20 shirt quilts become full bed quilts with one confident 6" border.
Sources and methodology
The layout solver tests every column count and chooses the grid with the fewest empty slots, preferring gently portrait proportions. Shirt panels cut at finished block + 1/2". Interfacing pieces cut about 1" larger than the panel, one per shirt from 20" wide lightweight fusible; yardage = shirts x (block cut + 1") / 36, rounded up to the half yard. Quilt center = columns x block + (columns - 1) x sashing in each direction. Cross-checked against published t-shirt quilt tutorials.
T-shirt quilt questions, answered
A lightweight woven or tricot fusible: stable enough to stop the stretch, soft enough that the quilt still drapes. Avoid stiff craft-weight interfacing unless you are intentionally making a quilt that can stand in the corner by itself. Buy the full yardage at once; dye lots do not matter but mid-project shop runs do.
Absolutely; a front and a back with printing count as two blocks, which is the thrifty path to a bigger quilt from fewer shirts. Count printable sides rather than shirts when you enter your number above. Sleeves with small logos can become cornerstones or a pieced label for the back.
When your shirt count does not fill a tidy rectangle, the open slots are opportunities: a plain block in the sashing fabric, a printed photo block, an embroidered name and date, or a pieced block in team colors. The calculator flags exactly how many fillers your layout needs so nothing surprises you at assembly.
Standard cotton or blend batting works beautifully. For quilting, keep stitching out of the printed designs where possible; dense quilting over old screen prints can crack them. A simple grid in the sashing lines, or gentle organic lines between logos, secures everything while letting the shirts remain the show.