Metric to Flotation Tire Size Calculator

Want to convert sizes like 265/75R16 to a flotation style like 31x10.50R16? Use our free calculator to find the flotation equivalent of your metric tire size, including approximate overall diameter and width.

Tire Size Conversion Calculator



Formula Used

To convert metric tire sizes to flotation:

Overall Diameter (inches) = (Section Width × Aspect Ratio ÷ 100) × 2 ÷ 25.4 + Rim Diameter
Section Width (inches) = Section Width ÷ 25.4


Example

265/75R16

  • Section width: 265 mm
  • Aspect ratio: 75%
  • Rim: 16″

Flotation Result:31.6x10.4R16

Why Convert Between Tire Sizes?

  • Shopping for off-road tires in metric-only stores
  • Replacing OEM tires with larger flotation types
  • Comparing fitment before upgrading

FAQs

Q. Is this conversion accurate?

It’s a close estimate. Some flotation sizes don’t match metric profiles exactly, but it’s good for visual size and fitment checks.

Q. Are metric and flotation sizes interchangeable?

Yes, if the overall diameter, width, and rim match. But always confirm load rating and clearance.

Q. What tires use flotation sizes?

Flotation sizes are popular in off-road, mud-terrain, all-terrain, and older light truck tires in the US.