Knitting and the Magic Formula

Increasing or decreasing stitches evenly within a set number of rows

Calculating the exact number of rows between each increase or decrease when knitting sleeves or other shaped pieces can sometimes be a bit 'hit and miss'. In the example shown on the right, 36 stitches need to be increased each side and the increases spread evenly throughout 140 rows.

The quick and easy method is to divide 140 by 36. This gives a result of 3.8888 rows. Not very practical to knit, so we probably interpret it as: Rows Increase 1 stitch at each end of every 3rd row 36 times = 108 Knit 32 rows straight = 32 Total 140 The problem now is that the shaping you wanted is not what you've got!!

Here we go with the maths ...

Step 1

Divide the number of stitches to be increased/decreased each side into the number of rows. From the diagram above, divide 140 by 36.

140 / 36 = 3 with a remainder of 32

Step 2

Subtract the remainder from the number of stitches required each side

36 - 32 = 4

Step 3

Add 1 to the whole number of rows from Step 1

3 + 1 = 4

Step 4

The final pattern, using these figures, would be:


1. Increase/decrease 1 stitch at each end of the 3rd row (whole number from Step 1) 4 times (result of Step 2).
2. Increase/decrease 1 stitch at each end of the 4th row (result of Step 3) 32 times (remainder from Step 1).

Finally, check ...

Rows

3 rows x 4 times =	12 rows
4 rows x 32 times =	128 rows
Total =	140 rows


Stitches

Inc/dec 2 sts x 4 rows =	8sts
Inc/dec 2 sts x 32 rows =	64 sts
Total increase/decrease =	72 sts (36 each side)