Crochet border stitch calculator

Too many stitches along the row ends of a blanket and the border ruffles; too few and it pulls in. This calculator works out the right pick-up rate from your gauge, writes it as a simple rhythm such as "7 stitches every 8 rows", and adjusts the setup round so a shell or picot border fits every side exactly.

How to use the calculator

1. Enter the stitches across the top, the rows up each side, and your stitch and row gauge.
2. Enter the border pattern's repeat (1 and 0 for a plain border).
3. Choose how many stitches each corner adds to a side: none, 2 (such as 3 sc in the corner) or 4.

How the calculator works

A border stitch is 1 ÷ stitch gauge wide, and a row end is 1 ÷ row gauge tall, so for the border to lie flat:

Stitches per row end = stitch gauge ÷ row gauge

That rate is turned into the nearest simple rhythm with no more than 12 rows, such as 7 stitches every 8 rows, and multiplied by the rows to give the plain count up each side. Across the top and bottom you pick up one stitch per stitch.

With a border repeat, each side plus its corner stitches is rounded to the nearest count that fits the repeat. You work that many, minus the corner stitches, on the setup round; the corners then complete each side.

Reading your results

• Stitches per row end: as a decimal and as a rhythm.
• Plain stitches up each side.
• Around after the setup round: and whether each side fits the repeat.
• Setup round: how to pick up along the row ends, and how many to work on the top, bottom and sides.
• Side counts: the plain count, the count to work on the setup round, and the count after the corners.

Worked example

A blanket 150 stitches wide and 112 rows tall, at 14 stitches and 16 rows per 4 in:

• Rate: 14 ÷ 16 = 0.875 stitches per row end, which is 7 stitches every 8 rows.
• Plain count up each side: 112 × 0.875 = 98.
• For a shell border worked over 6 plus 1, with 3 sc in each corner (2 extra per side): work 149 stitches across the top and 101 up each side. With the corners, that is 151 and 103, both 6 × k + 1.

Accuracy and limits

• The counts are exact and covered by our automated tests. The rhythm is the nearest simple fraction, so over a long side it can differ by a stitch from the exact rate; the side counts use the exact rate.
• It assumes the border is worked in a stitch similar to the blanket's. A much taller or shorter border stitch may need adjusting.
• Corners are counted in each side's repeat, so check your border pattern counts corners the same way.

Common mistakes

1. One stitch per row end on double crochet. A double crochet row end is as tall as two or more stitches are wide; picking up only one per row pulls the edge in.
2. Two per row end on single crochet. That makes the side ruffle.
3. Counting the corners twice. Each corner belongs to one count only: work the setup count, then the corner stitches.

Tips for more accurate results

• Mark the corners and count each side before starting the pattern round.
• Work a short test section and lay it flat before going all the way round.
• Work out the yarn for the border with the border yarn calculator.

Frequently asked questions