Knitting & crochet calculator
Yarn Substitution Calculator
Compare original and substitute yarn yardage to estimate how many substitute skeins you need and whether the yarn density looks close.
A yarn substitution has two separate questions: do you have enough yardage, and is the substitute yarn close enough in thickness and behavior to swatch well? Yardage tells you how many skeins to buy, but it does not guarantee matching gauge.
This calculator multiplies the original skeins by the original length per skein, then divides by the substitute length per skein. If you also enter skein weights, it compares yards per gram or ounce as a rough density check.
Worked example: if a pattern calls for 4 skeins at 220 yards each, the project needs 880 yards. A substitute with 180 yards per skein requires 5 skeins, because 4 skeins would only provide 720 yards.
Frequently Asked Questions
Is matching yardage enough for yarn substitution?
No. Matching total yardage only means you are less likely to run out. You still need to check gauge, fiber behavior, drape, and care instructions.
Why compare yards per weight?
Yards per gram or ounce gives a rough clue about yarn thickness. Similar values usually mean the yarns are closer, while very different values suggest the substitute may change gauge or fabric.
Should I buy extra substitute yarn?
Usually yes. Buy at least one extra skein when possible, especially if dye lots matter or the substitute yarn has less yardage per skein than the original.
Can this compare fiber content?
No. Fiber content affects stretch, drape, warmth, blocking, and wash behavior. This calculator only handles the arithmetic part of substitution.