Knitting & crochet calculators

What these tools solve

Use yarn estimators when you are shopping for a blanket, sweater, hat, scarf, or amigurumi. Switch to the knitting gauge calculator when you need stitches per inch or must resize a pattern. For stitch counts—not yarn—use the crochet blanket starting chain calculator, the cast-on calculator, and the even increase/decrease calculator. The yarn substitution calculator converts yards between CYC weight categories using FiberCalc planning midpoints.

How to measure

• Swatch in the stitch pattern you will use; wash and block the way you will finish the project.
• Measure stitches and rows over 4″ when possible—small swatches magnify counting error.
• Read the CYC category icon on the ball band; brand names like “DK” vs “worsted” can disagree.
• Note yards (or meters) and grams per skein so skein counts stay honest when labels differ.

Worked example: throw yardage

Area 50 × 60 = 3,000 in². FiberCalc worsted (#4) knit density is 0.55 yd/in² → 1,650 yd before waste; ×1.10 = 1,815 yd. At 200 yd/skein that is ceil(1,815 ÷ 200) = 10 skeins. Crochet uses the same density ×1.28 ≈ 2,323 yd for the same footprint. These density factors are site heuristics—documented on Methodology—not a Craft Yarn Council publication. Prefer a pattern’s tested yardage when you have one.

Worked example: cast-on from gauge

If your swatch is 18 stitches over 4″ (4.5 sts/in) and you want a 20″ hat circumference with a little negative ease, 20 × 4.5 ≈ 90 stitches before you adjust for pattern multiples. The cast-on calculator applies gauge and ease so you are not doing that multiplication on scrap paper mid-cast-on.

Common mistakes

• Estimating yardage before locking gauge—looser fabric usually burns more yarn per square inch.
• Mixing dye lots because the estimate was “almost” enough; buy an extra skein when lots are limited.
• Substituting by name only instead of matching CYC category, gauge, and fiber behavior.
• Using crochet and knit yardage interchangeably; crochet typically needs more yarn for the same area.

Guides and reference

Guides such as how much yarn for a blanket, sweater yarn, scarf skeins, crochet vs knit yarn, knitting gauge explained, and even increases explain the “why”; the tools do the arithmetic. See also CYC yarn weight standards and the needle & hook converter.