Finding tire size with rim?

Hey everyone. So I had a very nice gentleman just drop off a set of 4 aveo rims (the black steel ones) off of his written off aveo. I heard him talking yesterday at my work saying his wife wrote off her aveo and he said the only thing not wrecked were the tires and rims haha. So I said oh I have an Aveo...yadda yadda yadda... one thing led to another and he was very nice to drop them off to me this morning for free! Now the thing is... my aveo now has.... 14's I think on it? Still using the stock black steel ones on an '04 hatchback. These new ones he gave me measure 15 inches in diameter by 7 inches wide. The ones I currently have are 14 inches in diameter and 7 inches wide. How would I figure out the tire size for these new ones so that I can get some new rubber for them?? Thanks!

Just remembered the last tires I bought on my current rims were 18560R14. So would the new ones be something like 18560R15 then? Thanks!

A 195/50R15 would do better for you, and handle better. You could stay with a 185 wide, but you'd have to go 185/55/R15 to maintain the same diameter.

Use this calculator to find tires of the appropriate size: Tire size calculator

Argh hit the wrong button. So both of those would fit the new rim fine, correct? If 195/50R15 would be better though then I'll probably go with that. Thanks Daox!

if the rim measures 15" from lip to lip, its probably a 14" rim.

take it to a tire shop they should have a "caliper" that will measure for you, or you could take the lip tolip measure and subtract the distance to the first ridge on the inside of the tire.

or wait, do you know its a 15 inch rim?

The two stock sized tires for the Aveo are 185/60R14 and 185/55R15 for 14inch steel rims or 15inch aluminum wheels respectively.

Yeah, messed up a tad there. At first I measured from lip to lip... in which case the new rims I got were measuring at 16". Someone at work showed me how to properly measure them though, so it came in at 15" on the inside ridge. Which would make sense. I since edited my original post so it should make more sense now! So the new rim measures 15" by 7". Without removing my stock 14" tire from the steel rim its on, does anyone know the width of it? The new one looks like it may be a hair wider. I'm just wondering if this will effect my tire purchase. Or do the rims get wider when the overall width gets bigger?

Ok the stock steel 14" rims are 14x5" the 15" steel rims should be 15x6" And it will say that on the rim near the valve. ( on the rim lip ) On the option Alum rims most will be on the rear in side of the rim.