Are 285's and 33's the same size tires or are they one size lower than 33's

 

It takes more information then just 285.

In P metric the 285 is the tire width and your looking for an overall height.

In my case, having 18" wheels I believe a 33" is 305/65/18, but there are other ratios to accomplish the same overall height.

You can find tire size charts on google that will help with your specific application.

 

what he said^^^

a 285/75/r16 is a 32.6" tire if i remember correctly.

 

My 285-70-17 are 33.4x11.50x17

 

I have 305/70/17 or 33.8"

 

Plug metric size in here and it will convert to inches.
http://www.1010tires.com/TireSizeCalculator.asp

 

That size should be 32.70856" tall and 11.2204" wide...

*edit - would've been easier had I seen Jerry's post :-P

 

I've used many tire converters and they were all different, so I looked on my tires website and the sizes I mentioned is what it said, that's just my tires

 

If you get a 285x75x17 you'll have a 34 inch tire. A 295x70x17 is a 33.5 inch tire.