Crafts and sewing
Quilting, sewing, leatherwork, soap, dyeing and mould making: yardage, pleats, thread, batch sizes and dye weights from your own pattern and product figures.
Setting Triangle Calculator
The squares to cut for the side and corner setting triangles of an on-point quilt, how many of each, and the size of the finished top.
Fabric Width Conversion Calculator
Fabric to buy when your fabric is a different width from the pattern’s, rounded up to 1/8 yard.
Curtain Pleat Calculator
Pleat size and spacing for pinch-pleated curtains, the fabric widths and cut drops they need at your fullness, and the total fabric with any pattern repeat.
Saddle Stitch Thread Calculator
Thread to cut for a hand saddle stitch in leather, from seam, thickness and stitch spacing.
Silicone Mold Calculator
How much silicone mould rubber a poured block mould takes, by weight, from the mould box, the model and the product’s specific gravity, with part A and part B.
Soap Mold Batch Calculator
Oils to fill your soap mould, from its size and your recipe. It does not calculate lye.
Belt Blank Calculator
How long to cut a leather belt strap for your size, where to punch the holes, and how many belts a side of leather gives.
Dye Depth of Shade Calculator
Dye powder for a depth of shade, the stock solution to measure and the dye bath water.
Craft arithmetic is where patterns and product labels leave off. A quilt pattern gives a block size but not the setting triangles an on-point layout needs; a pattern envelope gives yardage for one fabric width but not the one in the shop; a leather pattern says nothing about how much thread a saddle stitch eats. The pages here do that arithmetic from the figures you already have: the block size, the pattern yardage, the stitch spacing, the mould's inside dimensions, the product's own mix ratio or specific gravity. Seam allowances, fullness, dye depth and waste are settings you can change, not rules the site imposes, because makers and products differ. Where a result is an estimate, such as fabric at a new width, which is proportional arithmetic and not a cutting layout, the page says so. Nothing here replaces a test piece, a test swatch or the maker's instructions.