How it works
Yards per sq in = 5 × stitches per inch ÷ 36 × stitch factor
Yards = width × length × yards per sq in × (1 + extra %)
Range = yards × 0.85 to yards × 1.15 (an estimate, not a promise)
The estimate is area times a rate in yards per square inch. The rate depends on how thick the yarn is and how much yarn the stitch packs into each inch.
For knitting we start from the Craft Yarn Council's standard stockinette gauge for each weight, using the middle of the range: 18 stitches per 4" for worsted, 13.5 for bulky, and so on. Textile research on plain knitting shows that the yarn in each square inch of relaxed fabric is close to 5 times the number of stitches per inch, in inches of yarn. For worsted that gives 0.625 yd per square inch, which matches what a typical worsted swatch weighs out at.
Other stitches use more yarn for the same area. We multiply by about 1.15 for garter stitch, 1.3 for single crochet, 1.2 for half double, 1.1 for double crochet and 1.05 for granny squares. These are averages, not rules.
Then we add an allowance for the border, weaving in ends and a swatch, 10% unless you change it. Your tension, hook or needle size and the stitch pattern can move the real figure by 15% either way, so we show that range. Buy to the top of it, or check that your shop takes returns.
Worked example
A 52" x 60" throw in worsted double crochet is 3,120 square inches. At 0.6875 yd per square inch plus 10%, that is about 2,360 yd (2,158 m), likely between 2,006 and 2,714 yd. With 364 yd skeins, buy 8 skeins (7 at the middle estimate).
Common mistakes
- Buying exactly the estimate. Dye lots run out; buy to the top of the range, as a missing skein from a different lot can show.
- Ignoring the stitch. Single crochet uses about 30% more yarn than stockinette for the same size blanket.
- Using the yarn weight name instead of your gauge. If you knit worsted on big needles for drape, you will use less yarn than the table; if you work tightly, more.
- Forgetting the border. A wide border or fringe can add 10 to 20% on its own.
An honest estimate. Yarn use depends on your tension, hook or needle size, the exact stitch pattern and the yarn itself. Treat the result as a planning number with a range of about 15% either way, buy to the top of the range from one dye lot, and keep the receipt. Weighing a swatch is the only way to be sure.
Last checked October 2026 against standard quilting and knitting math. Found a mistake? Tell us and we’ll fix it.