Cross-Stitch API

Cross-stitch and embroidery maths as an API, computed locally and deterministically — the design-size, fabric and floss numbers a cross-stitcher, embroidery designer or needlework-shop works a project out with. The design-size endpoint turns a stitch count and a fabric count (stitches per inch) into the finished size: size = stitch count ÷ fabric count, so a 140 × 98 design on 14-count Aida finishes at 10 × 7 inches (25.4 × 17.8 cm), smaller on 18-count and larger on 11-count because a higher count packs more stitches per inch — and it returns the total stitch count (width × height) that drives the floss and the hours. The fabric-needed endpoint adds a margin on every side to give the fabric to cut: design size + twice the margin per dimension, with the usual 3 inches per side for hooping, framing and finishing, so a 10 × 7 design wants a 16 × 13 inch cut. The thread-length endpoint estimates floss from the geometry of a full cross — the front two diagonals plus the back returns is about (2√2 + 2) ÷ fabric count inches per stitch — so 5,000 stitches on 14-count is roughly 1,724 inches, about 44 m, and it estimates the skeins given the number of strands (a 6-strand skein is ~8 m). Everything is computed locally and deterministically, so it is instant and private. Ideal for cross-stitch and embroidery pattern tools, needlework-shop and kit apps, and craft-project calculators. Pure local computation — no key, no third-party service, instant. Floss figures are planning estimates — buy a little extra and dye-lot match. 3 compute endpoints. For sewing yardage use a sewing API; for knitting gauge a knitting API.