Crochet pattern resizing calculator

Want a baby blanket pattern as a throw, or a scarf a little wider? This calculator resizes a flat pattern to any width and length at the pattern's own gauge. It keeps the new stitch and row counts on the pattern's repeats, and scales the yarn by the change in area.

How to use the calculator

1. Enter the pattern's size, stitches per row and rows. Use the stitches in a row, not the starting chain.
2. Optionally enter the yarn the pattern uses.
3. Enter the new width and length.
4. Enter the stitch repeat and the row repeat. If there is none, use 1 for each multiple and 0 for each plus.

How the calculator works

The pattern's own numbers give its gauge: stitches ÷ width and rows ÷ length. So you do not need to enter a gauge, as long as you crochet to the pattern's gauge.

Width and length are scaled separately, so you can widen without lengthening:

New stitches = pattern stitches × new width ÷ pattern width, rounded to the stitch repeat

New rows = pattern rows × new length ÷ pattern length, rounded to the row repeat

Yarn grows with area, which is the two scale factors multiplied together:

New yarn = pattern yarn × (new width ÷ pattern width) × (new length ÷ pattern length)

Reading your results

• New stitches per row and new rows: with the number of repeats, ready to work.
• Area multiplier: how many times more (or less) fabric the new size has.
• Yarn for the new size: the pattern's yarn times the area multiplier.
• New size as worked: rounding to the repeats can make the piece a little bigger or smaller than you asked; the note gives the actual size.

Worked example

A 30 × 36 in ripple baby blanket has 106 stitches per row and 90 rows, uses 750 yd, and is worked over a stitch repeat of 8 plus 2 and a row repeat of 4 plus 2. You want a 50 × 60 in throw.

• Scale factors: 50 ÷ 30 = 1.667 for the width, 60 ÷ 36 = 1.667 for the length.
• Stitches: 106 × 1.667 = 176.7, which fits the repeat as 178 stitches (22 repeats of 8 plus 2), about 50.38 in wide.
• Rows: 90 × 1.667 = 150, which is exactly 37 repeats of 4 plus 2.
• Yarn: the area is 2.78 times bigger, so 750 × 2.78 = about 2,083 yd.

Accuracy and limits

• The arithmetic is exact and covered by our automated tests, for flat rectangles worked at the same gauge as the pattern.
• The yarn estimate uses the size you asked for, not the slightly different size after rounding to the repeats, and it treats borders and fringe as part of the area.
• If the pattern's stitch count does not fit the repeat you entered, the calculator points it out; the pattern may count edge stitches separately.
• Bodies do not scale evenly, so do not resize fitted garments this way. Use the size grading calculator.
• Changing the yarn or gauge as well? Use your own gauge in the stitch and row calculator. To keep the pattern's size at a different gauge, use the pattern gauge converter.

Common mistakes

1. Entering the starting chain. "Chain 108, row 1: 106 dc" has 106 stitches per row. 108 does not fit 8 plus 2, which is why the calculator would warn you.
2. Buying twice the yarn for double the size. A blanket twice as wide and twice as long has four times the area, so it needs about four times the yarn.

Tips for more accurate results

• A narrow border grows with the edge length rather than the area, so scaling a small blanket up to a large one tends to overestimate the border's share slightly. That gives you a little spare.
• Buy all the yarn for the new size from the same dye lot.

Frequently asked questions