The urge to finish all the things bit me hard in August. I’ve finished a sweater and a cabled scarf, and have moved on to the Norma Blanket that I cast on in 2012. Part of the reason Norma still isn’t finished is because I’m knitting the expanded version. The other reason is that I wanted to use every yard of nature’s brown Fisherman’s Wool I had in my stash. That’s a grand total of 1,860 yards and the expanded version calls for only 1,500 yards.
Well, I finished the extended charts and still had a skein leftover which meant I had to chart the extra rows. But how many? To answer that question, I’ve been tracking my yardage. I use this trick a lot to figure out both how big I can knit something before binding off and when I need to stop to knit edging. It’s also pretty handy when you’re working on a pattern with growing repeats. Shawls, blankets, socks, sweaters, hats, and anything you can knit or crochet are all fair game.
To track your yardage, you’re going to need a scale that can measure in grams. I use a basic digital kitchen scale.
How often you weigh your yarn depends on what you’re making:
If you’re making something where the stitch count stays the same, like a scarf, you only have to measure once. After you’ve cast on and worked a few rows, weigh the yarn ball, and knit a few more rows.
If you’re making something small, - say a pair of stockinette socks or a hat - weigh, work at least 4 rows, and weigh the yarn again. The numbers will be more accurate over a larger number of rows than just one.
If you’re making something with a larger stitch count, like a shawl, you can knit a single row or pair of rows between weigh-ins.
If making something with repeats, measure the yarn before and after working one repeat. Even if the repeats get larger as you go, you’ll have a better idea of the amount of yarn required.
Weigh the yarn when the stitch pattern changes. A section of straight stockinette isn’t going to need the same about of yarn as a section of elongated stitches, cables, or slipped stitches.
Tracking yardage for projects where the stitch counts increase or decrease is a little more complicated. The good news is that, in most cases, the amount of yarn it takes to knit a row isn’t going to change that quickly. You don’t have to measure after every single row like I did for 100 or so rows of the Norma blanket. Maybe you measure yardage every 5, 10, or 15 rows. Just check regularly and keep your notes handy.
Once you have the numbers, it’s time to do the math. There are two options. The first is a little easier and gives an estimate. The second is more precise but requires more math.
Option 1: Divide the grams of remaining yarn by grams per row. The answer is the max number of knit-able rows, including the bind off. Next subtract the bind off and number of edge rows, if any, from the max row number. That answer is how many rows to work before starting an edging or binding off. If you’re working a repeat, divide the number of workable rows by the number of repeat rows.
As an example, here’s the math I did to find out how many more rows I needed to chart out for Norma. At the end of the chart I had 268 grams of yarn and was using 7-8 grams per row. Thanks to my meticulous measuring, I knew it would take a lot more stitches to need 9 or more grams per row.
268 grams / 7grams per row = 38.2 rows
268 grams / 8 grams per row = 33.5 rows
Since I’m going to be using more and more yarn with every row, I went with the 8 gram result which means 33 rows in the maximum I have yarn for.
33 rows - 7 edge rows - 1 bind off row = 25 rows
25 rows / 8 rows per repeat = 3.1 repeats.
So, I can knit 3 full repeats before starting the edging. Plus, I have a little wiggle room with the yardage, and hopefully not have to play yarn chicken during the bind off.
Option 2: Instead of working with row counts, this option focuses on finding stitches per gram.
Why worry with the number stitches per gram of yarn? It’s great for estimating the yarn required for patterns where the stitch count changes from row to row. If you’re designing a pattern, you can use stitches per gram of a swatch to estimate how much yarn the pattern will need before you cast on. The only downside is that you need to have a fairly accurate stitch count. In the example below, stitch count could refer to the number of stitches per row, per repeat, or the number of stitches worked between weigh-ins.
Stitch Count / Grams Worked= Stitches Per Gram
732 stitches / 7 grams = 104.5 stitches per gram
Armed with the number of stitches you can knit per gram and a spreadsheet of stitch counts, you can figure out exactly how much yarn a row, repeat, or bind off with need. Take the numbers with a grain of salt though because gauge changes and yarn isn’t always evenly spun. You can also follow the steps in the first method with stitches per gram as well.