Free Weaving & Spinning Calculators

Weaving and spinning involve precise ratios — sett, EPI, TPI, and drive ratios all need to be right before you start. These free calculators handle the math for weavers and handspinners so you can focus on fiber, not formulas. No signup required.

All Weaving & Spinning Tools

🏗️Weaving

Sett Calculator

Find the right sett (EPI) for your yarn and weave structure, plus warp length and reed substitution.

🌀Spinning

Spinning Calculator

Calculate drive ratios, twists per inch, and plying ratios for handspinning — the only online tool for spinners.

📏Knitting & Crochet

WPI Calculator

Enter your wraps per inch and instantly identify yarn weight, recommended needles and hooks, gauge range, and suggested projects.

⚖️Knitting & Crochet

Yarn Weights

Interactive yarn weight chart with US, UK, and Australian names — plus a substitution compatibility checker.

🗄️Knitting & Crochet

Stash Estimator

Estimate remaining yardage in partial skeins by weight, plus a yardage reference table for unlabeled yarn by weight category.

🧵Embroidery

Thread Converter

Instantly convert between DMC, Anchor, Cosmo, and Sulky embroidery thread numbers.

🧶Knitting & Crochet

Yarn Calculator

Calculate exactly how much yarn you need for any project — blankets, sweaters, scarves, and more.

More weaving and spinning tools are on the way

FiberTools continues to add calculators for weavers and spinners. Have a tool request? Drop us a line at hello@fibertools.app.

Browse all 31 tools on the homepage →