How substitution works
Midpoint yards-per-100 g for each CYC category come from typical ball-band ranges associated with the Craft Yarn Council weight system. Same grams ≈ similar coverage; yardage changes with wraps-per-inch.
Worked example
400 yd of worsted (#4) → DK (#3): DK has more yards per 100 g, so required yardage rises. Always swatch—drape still differs.
Tips
Match fiber content when possible. Check WPI if labels disagree. Needle or hook size usually changes with the new yarn.
Common mistakes
Matching only skein count without yardage; skipping swatches.
Reading ball bands
Look for the CYC yarn-weight icon (0–7), suggested needle/hook, and gauge. Wraps per inch (WPI) help when labels are missing: wrap yarn snugly around a ruler for one inch and count wraps. When substituting handspun, weigh the skein and measure length with a yarn meter or by skeining on a niddy-noddy of known circumference. Always knit a gauge swatch in the project stitch.
Limits and how to use the results
Estimates run only in your browser. Prefer a published pattern’s tested yardage when it conflicts with this planner. Density factors and assumptions are documented on the methodology page; legal terms cover planning-use limits.
FAQ
Can I substitute DK for worsted?
Sometimes, with more yardage and adjusted needle size. Swatch for gauge and hand.
How many grams in a skein?
Read the band. This tool converts using category averages when you only know yards or grams.