How Many Yards of Yarn for a Blanket? Sizes, Skeins, and Swatching

A baby blanket takes a few balls of yarn. A king-size one can take fifty or more. Where your project falls between those two depends on how big you're making it, how thick your yarn is, whether you're knitting or crocheting, and which stitch you use.

Start with a range for your blanket size, convert it into skeins (balls of yarn), then run a quick test at home to check the number against the yarn you've picked. Do that before you shop and you'll avoid the worst moment of any project, which is running out two rows from the end (or worse, two stitches).

What this article covers:

• How Many Yards of Yarn for a Blanket, by Size
• How Your Stitch Changes the Yardage
• Choosing Yarn Weight and Fiber for Your Blanket
• How to Estimate Yardage for Your Own Blanket
• How Many Skeins to Buy

How Many Yards of Yarn for a Blanket, by Size

Start with your finished size, since that’s where most of your total comes from. Most of these ranges are based on medium-weight yarn, also called worsted (not thin but not thick, either), which is the thickness most blanket patterns call for. Baby blankets are the exception, since they’re usually made with DK (Double-Knitting) weight yarn, one category lighter and thinner than worsted.

How Your Stitch Changes the Yardage

Two people can make the same blanket from the same yarn and finish over a thousand yards apart. The stitch is why.

You gain a lot of height in one row with a tall stitch like treble crochet, so you'll need fewer rows to fill the blanket and use less yarn overall. Those taller stitches leave small gaps between the loops, which is what crocheters mean by an open fabric. A throw worked that way comes in around 2,100 yards.

Single crochet is the opposite. It's a short stitch that packs many more loops into every inch for a dense fabric with no gaps, and the same throw then climbs past 3,300 yards. Double crochet sits between the two, which is one reason so many blanket patterns use it.

Knitting works the same way. Stockinette uses the least amount of yarn of the common stitches, made by knitting one row then purling the next. Purling is the reverse of a knit stitch and leaves a small bump instead of a smooth V.

Garter, which is knitting every row, packs more rows into the same height and takes about 20% more yarn than stockinette. Seed stitch alternates knit and purl within each row rather than between rows, so bumps scatter across both faces, and it also takes more than stockinette.

If you’re using textured stitches, you’ll need even more yarn. Bobbles, cables, popcorn stitches, puff stitches, and the crocodile stitch all pull extra yarn in behind the fabric where you can’t see it, so account for extra if your pattern calls for a lot of them.

Choosing Yarn Weight and Fiber for Your Blanket

Yarn weight means how thick the strand is, and it changes your total. Thicker yarn fills the same space with fewer stitches, so a throw in chunky yarn takes around 20 to 30% less yardage than the same throw in medium weight. Choose one category thinner, DK weight yarn, and you’ll need 20 to 30% more, and so on.

Fiber is the other thing you need to consider. Wool, alpaca, and other natural fibers for blankets are warm, light for their size, and springy enough to hold their shape for years. Cotton yarn is cool and breathable, which makes it lovely for a summer throw, but it’s denser than fibers like wool, so it can feel too heavy on a bed for some people. If the blanket is going to live on a kid’s bed or a dog-friendly sofa, acrylic yarn is a sensible choice because it’s safely machine-washable.

How to Estimate Yardage for Your Own Blanket

The ranges above are a starting point. In practice, your tension (how tightly you hold the yarn as you work) will be the biggest determining factor. This method works for knitting and crochet alike:

1. Crochet or knit a test square: Use the same yarn, hook or needles, and stitch you've chosen for the blanket, and aim for about 6 by 6 inches. This is called a swatch, and it's usually made to check stitch size. You're using it to weigh instead.
2. Flatten it and measure it: Wash the swatch first. Do it the same way you’ll wash the actual blanket. Once it's dry, lay the square on a table and pat it into shape, since crochet edges and stockinette both tend to curl. Measure the width and the length and write down what you get. It won't be exactly 6 by 6, and that's fine, as long as you use your own numbers from here on.
3. Weigh the same square in grams: Pop it on a kitchen scale. A 6-by-6-inch square in medium-weight yarn usually comes in somewhere between 9 and 18 grams. We recommend using grams rather than ounces because grams are more precise and easier to read on a scale, with 0.1 ounces equaling nearly 3 grams. If your square comes in under 8 grams, make a bigger one, for example 10 by 10 inches, so the scale has enough to read accurately.
4. Work out the yards in one gram of your yarn: Your yarn label lists both the yards and the grams in a full skein. Divide the yards by the grams to find how long a single gram of your yarn is.
5. Work out the yards in your square: Multiply your square’s weight by that figure. That tells you how much yarn you used to cover it.
6. Work out the yards in one square inch: Multiply your square’s width by its length for its area, then divide the yards by that area. This is the figure you’ll scale up, and it’s specific to your yarn, your stitch, and your tension.
7. Scale it up to your blanket: Multiply your blanket’s width by its length, then multiply that by your yards per square inch. That’s your total.

The whole sum, using our example numbers:

220 yards in a skein ÷ 100 grams per skein = 2.2 yards per gram
13 grams (your square) × 2.2 yards per gram = 29 yards in your square
6 inches × 6 inches (your square) = 36 square inches
29 yards in your square ÷ 36 square inches = 0.8 yards per square inch
50 inches × 60 inches (your blanket) = 3,000 square inches
3,000 square inches × 0.8 yards per square inch = 2,400 yards for your blanket

How Many Skeins to Buy

Yarn is sold by the skein, but your total is in yards, so the last step is dividing one by the other. Take your total yardage, divide it by the yards in one skein, and round up. Our 2,400-yard throw in 220-yard skeins works out to 10.9, so you’re buying 11.

Always calculate using the yardage on the label, not the number of skeins a pattern lists. Two skeins of medium-weight yarn can have a wildly different yardage depending on the brand, so a pattern calling for 10 skeins tells you very little unless you’re using the exact same yarn.

Buy one extra while you’re there, just in case (so 12 instead of just 11). Yarn is dyed in batches, and each batch gets a dye lot number printed on the label. Two skeins in the same color from different lots can look slightly different side by side, and lots sell out, so coming back for one more later is a gamble.

If you have a question about a particular yarn or lot, call us at (509) 536-7746 or email [email protected] and we’ll check it for you.

Frequently asked questions

What if I run out of yarn partway through?

Check the dye lot number on your labels before you buy more, since a different lot can show as a faint stripe across the blanket. If you can't match it, alternate the old and new skeins every two rows so the change blends in.

Will a bigger hook or needle save me yarn?

A little, but not as much as you'd hope. Looser stitches from a bigger hook or needle cover more ground, but they also make a floppier, more open blanket. Pick your tool based on the type of end result you want.

How do I work out yardage for a blanket with several colors?

Work out your total, then split it by how much of the blanket each color covers. Round each color up to a whole skein separately, since you can't borrow yards from one color to cover another.

Does a border need extra yarn?

Yes, and more than people expect. A border wraps the whole blanket, so a few rounds on a throw can take a couple of hundred yards. Add for it separately.