Yarn Substitutes Guide: How to Swap the Yarn a Pattern Calls For
How to pick yarn substitutes that work: match weight and gauge, plus fiber and yardage, check grist, work out how much to buy, and swatch before you start.
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You find the perfect pattern, and the yarn it calls for is sold out, too pricey or no longer made. That is when you need yarn substitutes. Swapping yarn is normal, and most patterns work fine with a different yarn. The trick is matching the right things, not just the weight on the label.
The short answer: good yarn substitutes match four things: yarn weight and gauge, plus fiber type and total yardage. Buy by yards, not by the number of balls. Then knit and wash a swatch before you cast on. If the swatch matches the pattern's gauge and the fabric feels right, the swap will work.
The Four Things Yarn Substitutes Must Match
1. Yarn weight. Start with the same weight category. A worsted pattern needs a worsted yarn, and an aran pattern needs an aran. The Craft Yarn Council weight system numbers each category, which helps when labels use different names. Our aran weight yarn guide explains the aran and worsted overlap.
2. Gauge. Weight categories are wide. Two worsted yarns can knit at quite different gauges. Compare the stitches per 4 inches on the pattern with the gauge on the new yarn's label. Gauge matters most of all for a fitted sweater.
3. Fiber. Fiber sets drape and warmth. It also changes stretch, and how the fabric behaves when washed. A wool sweater knit in cotton will hang heavier and stretch out more. Stay in the same fiber family when you can.
4. Total yardage. Balls and skeins come in many sizes. Always compare total yards, not the number of balls or the grams.
Check the Grist, Not Just the Label
Grist is how many yards you get per gram. Divide the yards on a ball band by its grams. Two yarns in the same weight category can have quite different grist.
A yarn with more yards per gram is finer or lighter. A yarn with fewer yards per gram is thicker or denser. If the grist of your substitute is close to the original's, the two will usually knit up at a similar gauge and weight.
Structure matters too. A single-ply yarn is soft and lofty but can pill. A plied yarn is rounder and sturdier. A chainette or brushed yarn behaves differently again. Try to match the look of the original: a smooth, round yarn for crisp cables, and a softer strand for drape.
How to Work Out Yardage for Yarn Substitutes
Work in yards from the start.
- Find how many balls of the original yarn the pattern calls for in your size.
- Multiply by the yards in one ball of the original. That is your total.
- Divide the total by the yards in one ball or skein of your substitute.
- Round up, then add one extra for your swatch and a little safety.
Example: your size needs 8 balls of a yarn with 110 yards each. That is 880 yards. Your substitute has 220 yards per skein. Divide 880 by 220 and you get 4 skeins. Buy 5.
Buy all of it from one dye lot. A second order months later may not match.
Fiber Swaps That Work and Ones to Avoid
- Wool for another wool: usually safe if weight and gauge match.
- Superwash for regular wool: fine for most projects, but superwash can grow when wet. Swatch and wash first.
- Acrylic for wool: works for blankets and kids' items. It will not block as crisply, and it may not show lace or cables as sharply.
- Cotton for wool: risky for garments. Cotton is heavier and has little stretch, so ribbing and fitted shapes can sag.
- Mohair or brushed yarn for smooth yarn: changes the look a lot. It hides stitch detail and adds a halo.
- Holding a yarn double: two strands of a fine yarn can stand in for one thicker strand. Swatch to check the gauge.
If the item will be worn next to the skin, used heavily or washed often, think about those needs before you pick a fiber.
Swatch Before You Commit
Knit a swatch at least 4 inches square in the pattern's main stitch. Wash and dry it the way you will wash the finished item. Then measure stitches and rows in the middle of the swatch.
If you get too many stitches, go up a needle size. If you get too few, go down one. Match stitch gauge first. Row gauge matters too for patterns worked to a set number of rows.
Look at the fabric as well as the numbers. A swatch can match gauge but still feel stiff or floppy. If the fabric is wrong for the project, try another yarn rather than forcing it.
When the Swap Changes the Pattern
Sometimes you cannot match gauge exactly, or you choose a different gauge on purpose. You can still make it work, but you need to do a little math.
If your stitch gauge is off, the finished width changes. Divide the pattern's stitch count by your stitches per inch to see the real width. For a scarf or a blanket, a small change may not matter. For a sweater, pick the pattern size whose stitch count gives you the width you want at your gauge.
If only your row gauge is off, length changes on parts worked to a set number of rows. Knit to the measurement in inches instead, where the pattern allows it. Sleeve and body shaping may need the decreases spread out differently.
When in doubt, choose a yarn that matches the stitch gauge. It is far easier than resizing a whole pattern.
Tools for Finding a Substitute
- YarnSub: enter the original yarn, and it suggests yarns with a similar weight and fiber, and a similar structure.
- Ravelry: its yarn database lists weight and yardage for many yarns, along with fiber and gauge. You can also see what other knitters used for the same pattern.
- Yarn shops: staff can often suggest a close match from what they stock.
These tools give you a shortlist. The swatch still has the final say.
Hand-dyed or specialty yarns, like Malabrigo Rios or a discontinued Rowan yarn, are some of the most common yarns knitters need to replace.
Yarn Substitutes FAQ
Can I use any yarn of the same weight?
Not always. Weight categories are wide, so also match gauge and fiber, then check yardage. A swatch confirms the match.
How do I know how much substitute yarn to buy?
Multiply the pattern's ball count by the original yards per ball. Then divide by the yards per ball of your new yarn and round up.
Why can't I just look at stitches per inch?
Gauge tells you the size, but not the fabric. Fiber and structure change drape and warmth, and how the piece wears.
What can I use instead of wool yarn?
Acrylic works for many blankets and kids' items. Alpaca and other animal fibers can work for garments. Cotton suits summer items more than fitted winter wear.
Do I need to swatch if the weights match?
Yes. Even two yarns labeled the same weight can knit at different gauges.
Verdict on Yarn Substitutes
Good yarn substitutes match the original yarn's weight and gauge, and its fiber and total yardage. Check the grist, buy by yards and not balls, and always knit and wash a swatch before you cast on. Do that, and almost any pattern can work with a yarn you can actually get.