When designing your own sweater, or even using up stash yarn, you'll want to estimate yardage to make sure you have enough for the project you're planning. Imagining your body as a giant rectangle is the quickest way to estimate yardage.
OK, you still need to have some yarn on hand, but it doesn't need to be the actual yarn you'll use, just a yarn of the same weight (Worsted, DK, fingering, etc).
Make a Swatch
- First, find some yarn of the same weight.
- Then measure off 10 yards (or 20 if it's fingering weight.)
- Knit up a swatch in the main stitch pattern
- Multiply width times height of your swatch.
This is your swatch in square inches. You'll need this number so jot it down.
The Pattern Schematic
Well, I exaggerated a little with that "giant rectangle" statement, though with a little re-imagining we end up with two skewed rectangles, or parallelograms. Look at your pattern schematic. Note the finished width and height of the body and sleeves. Don't have a schematic? Then just use your measurements and add ease. If the garment is knit in the round divide the circumference in two. Turn the front and one of the sleeves upside down in your mind and sandwich them together. You'll end up with two parallelograms, which are essentially rectangles.
Yardage Calculation
For me it's really helpful to imagine a sweater this way. Because now I can easily calculate how much yarn I'll need. You'll need the two numbers from your swatch:
- the number of yards you used for your swatch
- the number of square inches in your swatch
A. Calculate yardage for the body
- add the width (at widest point) to the measurement across the shoulders.
- Multiply this number by the sweater height. Jot it down... This is the total number of square inches for the entire body.
B. Calculate yardage for the sleeves
- add the widest width (or upper arm plus ease) to the wrist width.
- Multiply this number by the total sleeve length (or your shoulder to wrist measurement). This is the total square inches needed for both sleeves.
C. Add the numbers from A & B.
This is the total square inches for your sweater.
D. Divide the number in C by the square inches in your swatch
E. Multiply the number in D by 10, or the number of yards you used in your swatch.
An Example
I'm using a DK weight yarn. My swatch is 4" wide and 2" tall, and I used 10 yards to make it.
A. I'm making a sweater with set in sleeves, knit flat. The width at the hemline for my size 1X sweater is 25" (includes ease). The total height is 23". The shoulder to shoulder (or cross-back) measurement isn't given in the pattern, so I'll use my shoulder measurement, which is16".
(hem width + shoulder width) * total height = square inches
(25 + 16) x 23 = 943 square inches
B. For the sleeves, the finished wrist is 9" and my upper arm is 14". I'll add 2" ease to the upper arm for a finished widest width of 16". This should definitely be in your schematic, but this is the way I calculate finished sleeve width when I'm designing my own sweater. The total length of my sleeve is 25".
(sleeve width + wrist width) * total height = square inches
(16 + 9) * 25 = 625 square inches
C. Add A + B
943 + 625 = 1568 total square inches
D. Divide C by swatch square inches (remember, my swatch measures 4" x 2")
1568 ÷ (4 x 2) = 196
E. Multiply D by 10 (the yardage of my swatch)
196 x 10 = 1960 yds
That's it. I will need roughly 1960 yards of DK weight yarn for this sweater project in my size. With this method I know how much yarn I'll need, and can even modify the design to work with the amount of yarn I actually have.
Happy Knitting!
