Continuing on with my topic from last Wednesday. I'm going to work with specific examples. To keep things simple, I'm going to use whole numbers wherever I can. You may be dealing with fractions so you will need a calculator to be as accurate as possible.
Example 1: Converting to DK (Yarn Weight Number 3) from Worsted weight yarn (Yarn Weight Number 4). Both yarns are 100% wool with good stitch definition. The swatch shows the stitch pattern is attractive when worked in a smaller scale. DK is a lighter weight yarn so less ease is required. To achieve the same look of the original garment, when less ease is required, it means it is safe to round down, when adjusting fractional numbers.
Your Gauge DK: 22 stitches, 28 rows = 4 inches.
Original Gauge (the pattern) Worsted: 18 stitches, 24 rows = 4 inches.
Stitches 22 ÷ 18 = 1.22
Rows 28 ÷ 24 = 1.17
Example 2: Converting to Worsted weight yarn (Yarn Weight Number 4) from DK (Yarn Weight Number 3). Both yarns are 100% wool with good stitch definition. The swatch shows the stitch pattern is attractive when worked in a larger scale. Worsted is a heavier weight yarn so more ease is required. To achieve the same look of the original garment, when more ease required, it means it is safe to round up, when adjusting fractional numbers.
Your Gauge in Worsted: 18 stitches, 24 rows = 4 inches.
Original Gauge (the pattern) DK: 22 stitches, 28 rows = 4 inches.
Stitches 18 ÷ 22 = .82
Rows 24 ÷ 28 = .86
To compare to the more common way of calculating ...
To get the cast on for a 20 inch garment back, the calculation is:
DK 20 inches x 5.5 = 110 stitches
Worsted 20 inches x 4.5 = 90 stitches
Fudge Factor Method
90 stitches (worsted) x 1.22 (the fudge factor) = 109.8 stitches
110 stitches (DK) x .82 (the fudge factor) = 90.2 stitches
Continuing with Example 2, to convert the pattern, work through it section by section. Everywhere the instructions give a stitch number, multiply the number by the Fudge Factor. If the pattern instructions are to cast on 110 stitches, multiply 110 x .82 the result is 90 stitches for the cast on. The conversion can be to a higher or lower stitch number, it is simply a comparison ratio of achieved gauge to the original gauge.
Next, do the same thing with the row gauge. Divide your row gauge by the pattern row gauge to get the conversion ratio. In this example Rows 24 ÷ 28 = .86. Everywhere the pattern tells you to knit rows you multiply by the fudge factor. In many cases, the pattern will give you a measurement instead of a number so no calculations are required. The more complex the original design, the more complicated the conversion process will be.
If you are converting a pattern with multiple elements, do consider how the changes will impact the overall design. Changes of more than one or two stitches or rows per inch will affect panel widths and the size of motifs in a significant way. If you are reproducing an intarsia or fair isle design, you must consider the changes in motif size. Each will be larger or smaller according to your conversion ratio and, the garment will look very different from the original.
Designs with a single all over stitch pattern will not be impacted. However you should review band widths and lengths for potential adjustment.
Once you have your new stitch numbers calculated they may require adjustment to match up with stitch multiples in the pattern.
Your gauge in Worsted requires a 90 stitch cast on.
Original pattern gauge in DK required a 110 stitch cast on.
Pattern repeat is a multiple of 6, with 2 selvedge stitches. In DK 110 stitches - 2 = 108 ÷ 6 = 18
In Worsted 90 stitches - 2 = 88 ÷ 6 = 14.66. Adjust the number to a whole repeat of:
6 x 14 = 84 add 2 selvedge stitches equals a cast on of 86 stitches
6 x 15 = 90 add 2 selvedge stitches equals a cast on of 92 stitches.
Using a heavier yarn means more ease is required therefore I would recommend taking the stitch numbers up to correct for stitch multiples in this situation.
Part 3 will be posted next Wednesday. I'll discuss sleeve adjustments and how to recalculate yarn amounts.
Part 1 can be found here.http://knittingrobin.blogspot.ca/2012/10/the-fudge-factor-part-1.html
Part 3 can be found here.