Crochet pattern grading calculator

Designers grading a pattern across sizes spend hours fitting each size to the stitch repeat. This calculator grades one panel across nine women's sizes from XS to 5XL, fits every size to the repeat, shows how far each lands from its target, scales the yarn from the size you made, and writes the counts in the usual bracket notation.

How to use the calculator

1. Enter the ease for every size and your stitch gauge.
2. Enter the stitch repeat and any seam allowance per panel edge.
3. Choose the stitch, for the chain count.
4. Optionally choose the size you made and enter the yarn it used.

How the calculator works

The bust sizes are the upper end of each Craft Yarn Council women's size range: XS 30, S 34, M 38, L 42, XL 46, 2XL 50, 3XL 54, 4XL 58 and 5XL 62 in.

Finished chest = bust + ease

Panel stitches = (finished chest ÷ 2 + 2 × seam allowance) × stitch gauge, rounded to the nearest count that fits the repeat.

Chain = stitches + the turning chain for your stitch

The actual finished chest is worked back from the rounded stitch count, so you can see how far each size lands from its target. If you entered the yarn for one size, every other size's yarn is scaled by its finished chest.

Reading your results

• Pattern lines: the chain and row 1 for one panel in bracket notation: XS (S, M, L, XL) [2XL, 3XL, 4XL, 5XL].
• Grading table: for each size, the bust, finished chest, stitches, chain, actual size with its difference from the target, and the yarn.
• Warnings: if two sizes land on the same count, or one repeat is wider than the step between sizes.

Worked example

Ease 4 in for every size, 4 stitches per inch, a repeat of 6 plus 2 and double crochet, with no seam allowance:

• Chain 70 (76, 88, 94, 100) [112, 118, 124, 136].
• Row 1: 68 (74, 86, 92, 98) [110, 116, 122, 134] dc.
• The repeat moves each size by up to 1 in: S comes out 37 in instead of 38, M 43 in instead of 42.
• If size M used 1,200 yd, the table scales it from 949 yd for XS to 1,870 yd for 5XL.

Accuracy and limits

• The arithmetic is exact and covered by our automated tests. The front and back are graded as identical halves.
• Only the chest is graded. Shoulders, armholes and lengths do not grow at the same rate as the bust; grade them from a size chart.
• Yarn is scaled by the finished chest only. Larger sizes are usually longer too, so add for the extra length and sleeves.
• A large stitch repeat can only land on some sizes; the calculator warns you if sizes collide.

Common mistakes

1. Grading everything by the bust. Neck, shoulders and armholes need their own measurements.
2. Ignoring the actual sizes. A big repeat can make neighbouring sizes 2 in apart instead of 4; check the "actual" column.
3. Using one ease for every style. Fitted and oversized designs need different ease.

Tips for more accurate results

• Work out ease and panels for one size first with the garment ease calculator.
• For a flat item such as a blanket or scarf, use the pattern resizing calculator instead.
• Test-make at least two sizes, ideally the smallest and largest, before publishing.

Frequently asked questions