Short is worse than spare
Suppose you need 160 inches of fabric and the shop sells eighth-yard increments. Rounding down to 4⅜ yards = 157½ inches leaves you 2½ inches short. Rounding up to 4½ yards = 162 inches leaves 2 inches extra. The backing calculator uses this upward-rounding rule.
What “next unit” means
| You buy | Sold in | Example |
|---|---|---|
| Fabric | ⅛ yard (4½ in) | 160 in needed → 4½ yd |
| Yarn | Whole balls or skeins | 3.2 skeins needed → buy 4 |
The yarn row is an example of the same arithmetic, rather than a released yarn-purchase calculator. Check the increments your shop sells. An amount already on an increment stays the same. Compare the exact amount with the rounded one to see how much extra you will have. See eighth of a yard.