tire conversion help please

[prorida]

so to adjust my spedo on EFIlive i need to know metric measurements. i have yet to find a inches to mm chart online. i have 36x13.5r20 the interco website says that the tires get 598 revs per mile, in the efilive conversion that drops my tire diameter to a 33!!!!!!!!!!

anybody got any ideas to get the correct measurements?

 

[Noreaster]

345/60/20
http://www.dakota-truck.net/TIRECALC/tirecalc.html

 

[prorida]

343/59R20 is what i came up with, thanks for the chart. let see what this looks like with efi!:thumb:

 

[Noreaster]

I rounded it up

 

[prorida]

i just found that out i rounded down to a 340/60r20 for tire wear. thanks again Noreaster!!!