How much yarn per granny square? Weigh, then multiply

What published patterns use per square

We found eight granny-square blankets that give both a square size and a yarn quantity. Most designers give the whole blanket, so we divided by the number of squares. Those figures include the joining and the border, and they’re buying quantities with some yarn left in the last balls. Treat them as upper figures for the square itself. We haven’t made these blankets ourselves; the quantities are the designers’ own.

Two patterns separate the square from the rest. B.Hooked says ‘about 70 yds per square’ for an 8in square in medium-weight yarn, which is 64 m. The Simply Yarn baby blanket uses about 100 m of each of 10 colours for 10 small squares each, so about 10 m a square, with 650 m of cream on top for the joining rounds and border.

Weigh several squares

For identical single-colour squares, weigh three or more together and divide by the count. Three squares weighing 24 g give 8 g each. Weigh only the yarn and trim the tails the same way each time. Weighing several at once also makes a kitchen scale’s 1 g steps matter less.

Turn grams into metres

Use the label of the yarn you weighed. Stylecraft Special DK has 295 m in 100 g, so an 8 g square is 8 ÷ 100 × 295 = 23.6 m. For a yarn with 200 m per 100 g it would be 16 m.

Don’t weigh a multi-colour square and split it evenly. Weigh a square for each colour layout, or make a single-colour test square.

Multiply by your grid

Six squares across and eight down is 48 squares. At 16 m each that’s 768 m before joining or a border. If each square measures 12 cm, the grid comes to 72 × 96 cm. The join and border then add to both the size and the yarn.

Add joining and border yarn separately

Estimate the joining yarn as its own figure. Say 60 m for a sewn or slip stitch join in the same colour, the top of the 3 to 6 metres per metre of seam in our guide to joining granny squares (82 edges of 12 cm is 9.8 m of seam): 768 + 60 = 828 m. Work out the border on top of that, and if it’s a different colour, give it its own shopping row.

Borders can take a lot. In the Simply Yarn baby blanket, the cream for joining and edging is 650 m, more than half the 1,000 m in the coloured squares.

From metres to balls

At 200 m a ball with nothing in your stash, 828 m means 5 balls. If you already have 100 m of the same yarn and shade, the new yarn has to cover 728 m, which rounds to 4 balls. The square planner hands the length to the shopping planner, which deals with stash and packs.

Tools for blocking and joining squares

Blocking squares to the same size before you measure them makes the grid estimate more reliable. A blunt tapestry needle joins squares and weaves in ends without splitting the yarn.

Common questions

Sources and scope

• simply-yarn.com/crochet-patterns/easy-free-granny-square-baby-blanket-crochet-pattern
• sarahmaker.com/granny-square-blanket/
• attic24.co.uk/posts/harmony-blanket/
• www.anniedesigncrochet.com/scrap-buster-cal-free-granny-crochet-blanket-pattern/
• bhookedcrochet.com/2024/10/08/how-to-make-a-classic-granny-square-blanket-in-3-sizes/
• www.jerasjamboree.co.uk/granny-square-blanket-blanket-blossom-cottage/
• www.anniedesigncrochet.com/floral-granny-square-blanket-free-crochet-pattern/
• www.stitchandstory.com/blogs/our-journal/chunky-granny-square-blanket
• www.stylecraft-yarns.co.uk/yarns/special-dk
• www.stylecraft-yarns.co.uk/yarns/special-aran

Sources checked 2 October 2026. Label facts come from the linked references; worked purchase examples and arithmetic are our own illustrations. Original pattern and product names retain their source spelling.