The yarn you need is discontinued. You have 8 skeins of something beautiful that doesn't match anything in the pattern. You want to use a cheaper alternative. Every one of these situations requires the same thing: precise gauge maths applied to every stitch count in the pattern.
Most crafters either skip it (and frog later), spend way too long with a calculator (and still get it wrong), or ask on forums and wait days for an answer.
Try StitchPlus free →A deterministic JavaScript calculator computes every ratio to 4 decimal places before AI touches your pattern. The AI writes the instructions. The code does the numbers. Every time.
Enter your bust, body length, and arm length. StitchPlus reads the size table and tells you which size to make — then calculates every stitch count precisely for your measurements and ease preference.
See a jumper you love in a store? Photograph it. AI identifies the construction, neckline, sleeve type, and stitch pattern — then generates a full pattern sized to your measurements.
"I had 8 skeins of Drops Karisma that didn't match anything on Ravelry. Scanned the pattern, entered my gauge, got the full recalculated instructions in 2 minutes. I would have given up on this project."
"As a pattern designer I used to spend hours answering 'can I use X yarn instead?' Now I put the widget in every pattern PDF. My customers self-serve and my inbox is quiet."
"We run it on a tablet at the counter. When a customer asks 'can I use this instead?' — we open StitchPlus and have the answer in under a minute. It's become part of how we serve customers."