Calculations use theoretical geometry. Actual manufacturer dimensions vary by up to ½" — confirm with the tire manufacturer's published specifications before purchasing.
Flotation sizing is common on trucks, Jeeps, and off-road builds. Metric sizing covers nearly all passenger cars and crossovers. Enter any tire size in either format and the converter will show the equivalent in the other. For flotation sizes, the result shows both the mathematically exact metric equivalent and the nearest commercially available standard metric size, along with how closely the diameters match.
The nearest standard size shown is a starting point, not a guarantee. Flotation and metric sizes use different nominal conventions, and the calculated equivalent will often land between two standard sizes. Manufacturers also publish measured dimensions that differ from the theoretical formula by up to half an inch, so the actual diameter of a tire on the shelf may not match what the math predicts. Always confirm with the manufacturer's published spec sheet before purchasing.