Sorry for the ambiguous thread title. I wasn’t sure how else to phrase my question is such a short space.

Okay, this is involving garbage bags, and what diameter garbage can they’ll fit over. So, for instance, we have a garbage can with a 19 inch diameter, that’s a 59.7 inch circumference. Now we’re not sure what garbage bags to buy for it. They come in a variety of sizes, from 24 to over 30 inches, across the top, flat.

So, given that data, how do we know what garbage bags will fit our garbage can?

Already we’ve figured that it’s not the standard straight across dimension of the bag times pi. So, in the shop we have garbage bags that are 25 inches lying flat. That times pi give us 78.5 inches, which should fit over out 59.7 inch circumference garbage can, but it doesn’t.

Obviously the bag is losing size as soon as it’s opened up. I’ve tried breaking down the garbage bag dimension by half, but that still doesn’t work. For our 25 inch bag, that’s 12.5, which by looking at a opened bag, the diameter is much greater than that.

So, essentially, using the garbage bag example and given just the size of the opening lying flat, how can we determine what circumference garbage can the bag will fit over? Or conversly, given the size of the garage can, what size bag will fit over it?

My apologies in advance for any terms used inappropriately. I hope I’ve clearly conveyed what my question is. Oh, and the bags don’t give a capacity, and the sticker on the garbage can with capacity is missing. Either way, I’d like to find out how to determine if the bag will fit with the data given above. It’s kinda annoying that I couldn’t figure it out. Thanks for your time.