How much yarn do I need for a crochet blanket?

The quick answer, by blanket size

Find the size closest to the blanket you have in mind. Use the lower number for solid stitches or corner-to-corner, and the higher one for granny stripes or granny squares. If your pattern gives its own quantity, trust the pattern over this table.

Baby and throw sizes are common ones listed by the UK designer Jera’s Jamboree. Bed sizes are UK mattress tops, as listed by Which? magazine. If you want the blanket to hang down the sides, measure the extra drop and add it to both dimensions before you estimate.

Where the numbers come from

We opened each pattern page and noted the finished size and the yarn the designer tells you to buy. Then we divided the total length by the blanket’s area to get metres per square metre. Most designers describe their sizes as approximate, and a quantity to buy usually leaves a little over, so treat these as buying figures rather than exact consumption.

We haven’t crocheted these blankets ourselves. The quantities are the designers’ own, and every pattern is linked at the bottom of this page so you can check them.

DK and aran need a similar number of balls

Aran is thicker, so a square metre of aran fabric takes fewer metres: 1,110 to 1,570 in the aran patterns we checked, against 1,780 to 2,530 in DK. But a 100g ball of Stylecraft Special Aran also holds less yarn, 196m against 295m for the DK. The two effects roughly cancel out.

So if you’re torn between DK and aran for a single-bed blanket, budget about the same number of 100g balls either way. The aran version will usually work up faster, because each stitch covers more ground.

Stitch pattern changes more than you’d expect

The clearest comparison comes from one designer. Attic24’s Cosy Stripe and Granny Stripe are both in Stylecraft Special DK, both on a 4mm hook, and both roughly 120cm wide. Cosy Stripe asks for 15 balls at 120 × 180cm. Granny Stripe asks for 18 at 120 × 175cm. Per square metre, the granny stripe needs about 23% more yarn.

Her Harmony blanket, made from 126 granny squares joined as you go, sits right next to the Granny Stripe. Granny stitch looks open, but its three-treble clusters pack in a lot of yarn. In our DK group, the corner-to-corner Jewel blanket came out lowest, though it is a different designer’s kit. Among the aran patterns, moss stitch was the most economical.

Super chunky: fewer metres, heavier blanket

The two super chunky blankets used only 620 to 720 metres per square metre, but super chunky yarn has very few metres in each ball. The ribbed Handy Little Me throw uses 20 balls of 100g for 127 × 152cm, so it weighs around 2kg. Attic24’s Cosy Stripe in DK is bigger, at 120 × 180cm, and needs 1.5kg.

If you want a weighty blanket that grows quickly, super chunky does that. Don’t pick it to save on yarn without pricing the balls first.

Narrow the range with a weighed swatch

Crochet a swatch 20cm × 20cm in your yarn, hook and stitch, then weigh it. A 20cm square is one twenty-fifth of a square metre, so multiply its weight by 25 to get grams per square metre.

Say the swatch weighs 30g. That’s 750g per square metre. A 120 × 175cm blanket covers 2.1 square metres, so 750 × 2.1 = 1,575g, which is 16 balls of 100g. Add your border separately, because a swatch doesn’t include one. If you’re making squares, the granny-square planner does this calculation from weighed squares instead.

Turn the estimate into a shopping list

Striped and multicolour blankets need each colour rounded up to whole balls separately. Ten colours that each need a third of a ball still mean ten balls, not four. Buy the main colour in one go if you can, so the dye lot matches.

Put each colour into the shopping planner as its own row, then compare single balls with packs before you order.

Common questions

Sources and scope

• attic24.co.uk/posts/cosy-stripe-blanket/
• attic24.co.uk/posts/granny-stripe-blanket/
• attic24.co.uk/posts/harmony-blanket/
• www.woolzone.co.uk/product/jewel-c2c-crochet-blanket-kit/
• www.anniedesigncrochet.com/scrap-buster-cal-free-granny-crochet-blanket-pattern/
• catherinecrochets.com/easy-moss-stitch-crochet-blanket-a-relaxing-crochet-project-to-snuggle-up-with/
• sunflowercottagecrochet.com/relaxing-waves-blanket-easy-and-free-crochet-blanket-pattern/
• themoulehole.com/2021/10/07/free-chunky-yarn-crochet-blanket-pattern-midnight-hour-blanket/
• www.handylittleme.com/chunky-crochet-blanket-pattern/
• www.jerasjamboree.co.uk/baby-blankets-to-crochet/
• www.jerasjamboree.co.uk/marlowe-crochet-lap-blanket-pattern/
• www.which.co.uk/reviews/mattresses/article/uk-mattress-sizes-bed-mattress-size-guide-aDx4r9b4T99o
• www.stylecraft-yarns.co.uk/yarns/special-dk/
• www.stylecraft-yarns.co.uk/yarns/special-aran/

Sources checked 1 October 2026. Label facts come from the linked references; worked purchase examples and arithmetic are our own illustrations.