As of 2015, several independently operated websites offer tire size charts and conversion charts that list tire diameter, including Tire-Size-Conversion.com, TireRack.com and Maxima.org. Many tire retailers provide tire size calculators and tire sizing guides, including BFGoodrichTires.com.
Tire-Size-Conversion.com provides tire size charts by diameter and by wheel size. On the diameter chart, users can select anywhere from a 21-inch diameter to a 41 to 54-inch diameter to see the corresponding wheel size and tire options. The chart provided by TireRack.com focuses on diameter comparisons specific to light truck tire sizes.
BFGoodRichTires.com offers a tire size listing by rim size in a format that is similar to a size chart. Users can select rim diameters ranging from 14 inches to 22 inches in order to find the right tire size for their vehicle.