Crochet related maths question

[MichaelBurnhamFan]

I’m using up some leftover yarn making 8 inch squares for a friend who is turning them into blankets for charity. And trying to work out how many squares I could get from a ball.

My mum gets about 7 squares (knit, garter stitch) to a ball of the same yarn (its a dk acrylic) But the ones she’s making are 6 inches.

If it helps I’m doing crochet granny squares.

Impossible to tell, it would depend on the stitch and your tension and not really comparable to knitting.
I would make one square and weigh it and work it out from the weight of the ball

6 inch squares are 36 sq. In
8 inch squares are 64?sq. in

Therefore you should get 7 x 36/64
= 3,9 squares per ball at the same tension as your mum.

Yep I'd do what Dotty says! Make 1 and weigh it, they you know how many you'll get out of a ball.

Yep, by weight is the only way to do this I'm afraid!

Thanks everyone!

I appreciate that OP has replied, but in case someone else reads the thread and has a similar question:

That would be logical if they had the same tension and were both knitting, but OP’s friend wants to crochet the squares.

Crochet typically uses more yarn than knitting for the same general effect, I understand. I have no idea why, when granny squares have more ‘holes’ than stocking stitch ones, but it may be that crochet in DK on a 4mm hook seems to be thicker (in the third dimension sense) than knitting on no 4 needles.

It may not matter much, but different balls of acrylic can have different yardages.

For example, the very popular Stylecraft Special DK has 326 yards in a 100g ball and this one from Knitting Room has only 200 yards in 100g.

Edit: so just weighing the balls may not give you the full picture. It’s the best I could suggest, along with apps, though, unless you know what yarn you’re using. If it’s all the same yarn it wouldn’t matter.