Crochet: sizing up yarn - do I still just need the same length?

[HereIGoAgainAndAgainAndAgain]

Exactly what it says above! If I’m going from dk to aran and need (eg) 120m dk, do I still only need 120m aran? I can’t get my brain round that but that’s what I’ve been told 🤯

I always find I need a bit more, especially if you've gone up a hook size too. The finished item will be bigger too- sorry if that's obvious!

Sizing is irrelevant - it’s a toy 🧸. I just need to know if I’ll have enough yarn! It’s on sale with only 3 balls and I’m trying to save pennies!

You will need a longer length as the stitch will be bigger therefore using more yarn - you can do a quick check by knitting/crocheting a set amount of stitches using the original yarn and needle/hook size, then repeating with the substitute yarn/needle/hook. There may be some sort of rough conversion tool online if you search for it.

You will probably need a bit more if you use the same size hook, it will be a more dense fabric. If you size up your hook it will be looser but you will need a lot more yarn. The best thing to do (if you've got the time and patience) is to do a small swatch with both yarns then unravel them and measure the yarn used to get a rough idea of how much more you might need.