T-Shirt Quilt Layout Planner
The block size comes from your smallest design, so one small shirt shrinks every block. The quilt area peaks — dropping more is not better.
| Drop | Block size | Blocks | Quilt | Area | vs keeping all |
|---|
One small shirt shrinks every block
A t-shirt quilt trimmed to a common size takes that size from the smallest design in the pile. So one modest chest logo drags every other block down with it — and nobody notices until the rotary cutter is out and sixteen good designs have been cut down to match the worst one.
It is worth seeing as a number. On the sample pile above, keeping all sixteen shirts gives 10-inch blocks and a 1,600 square inch quilt. Dropping just the smallest raises every remaining block to 11 inches — more total quilt from fewer shirts.
But dropping more is not always better
This is the part that makes it worth calculating rather than guessing. The quilt area peaks and then falls:
| Shirts dropped | Block size | Blocks | Total area |
|---|---|---|---|
| 0 | 10″ | 16 | 1,600 sq in |
| 1 | 11″ | 15 | 1,815 sq in |
| 2 | 12″ | 14 | 2,016 sq in — peak |
| 3 | 12″ | 13 | 1,872 sq in |
| 4 | 12.5″ | 12 | 1,875 sq in |
| 5 | 13″ | 11 | 1,859 sq in |
The reason is exact: dropping a shirt only helps when it actually raises the minimum. Discard a duplicate of the smallest size and you lose a block and gain nothing at all. So there is a genuine optimum, it is usually not zero, and it is usually not "all the small ones" either.
Or keep everything and let sashing absorb it
The trimming problem only exists because every block has to be the same size. It does not have to be. Set the column widths by the widest shirt in each column and let sashing take up the difference, and nothing gets cut down to the smallest — the quilt simply has slightly uneven internal spacing, which nobody has ever noticed in a finished t-shirt quilt. It is more fiddly to assemble and it saves every design at full size. Worth considering before deciding which shirts to lose.
Notes
- Measure the design, not the shirt. What matters is the printed area you want to keep, plus a little breathing room around it — not the size of the garment.
- Interface the knit before cutting. T-shirt jersey stretches in every direction and will not behave in a pieced quilt. Fusible knit interfacing on the back of each block is the standard fix and it is not optional.
- Some shirts are worth more than an inch. The arithmetic here maximises area, and that is not always the right objective — a shirt from the year that mattered earns its place whatever it does to the block size.
- Cut a test block first. Interfacing shrinks jersey slightly and a pressed block is not the size of an unpressed one. Do one before committing sixteen.
How to use
- Measure the usable design area on each shirt, not the shirt itself.
- Enter the sizes and read where the quilt area peaks.
- Decide whether the shirts it suggests dropping are ones you can lose.
- Interface every block before cutting — jersey stretches in all directions.
Frequently asked questions
What size should t-shirt quilt blocks be?
If every block is trimmed the same, the size comes from the smallest design in the pile — which means one modest chest logo drags every other block down with it. Measure the printed area on each shirt before deciding, because the answer is set by the worst one.
Should I drop the smallest shirts?
Often yes, and the arithmetic can be striking — dropping one small shirt can produce a bigger quilt from fewer shirts, because every remaining block grows. But it is not simply "drop more, get more".
Why does dropping more shirts eventually make the quilt smaller?
Because dropping a shirt only helps when it actually raises the minimum. Discard a duplicate of the smallest size and you lose a block and gain nothing at all. So the total area rises to a peak and then falls, and there is a genuine optimum worth finding rather than guessing at.
Can I keep every shirt at its own size?
Yes — set the column widths by the widest shirt in each column and let sashing absorb the difference. Nothing gets cut down to the smallest, the internal spacing is slightly uneven, and nobody has ever noticed that in a finished t-shirt quilt. It is fiddlier to assemble and it saves every design at full size.
How much fabric am I throwing away by trimming?
The tool shows it as a percentage of the design area you actually have. On an uneven pile it can be a quarter or more, which is the real argument for the sashed approach.
Do I need to interface t-shirts?
Yes, and it is not optional. Jersey stretches in every direction and will not behave in a pieced quilt — fusible knit interfacing on the back of each block is the standard fix. Cut a test block first, because interfacing shrinks the knit slightly.
What should I measure on each shirt?
The printed design plus a little breathing room around it — not the garment. A large shirt with a small chest logo gives you a small block, and that is exactly the case that sets the size for everything else.
Should I always take the biggest quilt?
No. The arithmetic maximises area and that is not always the objective — a shirt from the year that mattered earns its place whatever it does to the block size. Use the table to see the cost of keeping it, then decide.
Does this send anything anywhere?
No. Everything is calculated in your browser and nothing is stored or uploaded.
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