Tire Size Converter — Metric/Inches

Exact geometry first. Then the closest size you can actually buy — with the difference stated.

Convert 35x12.50R20 to metric, or 275/60R20 to a flotation-style reading.

How to read 275/60R20
sidewall (60)rim 20"tread275 mm
  • 275 is the section width in millimetres, measured sidewall to sidewall.
  • 60 is not millimetres: it is the sidewall as a percentage of the width. Here, 60% of 275 = 165 mm per side.
  • R means radial construction. 20 is the rim diameter in inches.
  • Overall diameter is the rim plus two sidewalls. That is why changing the 60 changes ride height.

What it does

Converts metric ↔ flotation. You get the exact inch or millimeter reading, then the nearest common commercial size and how far it sits from exact.

How to use it

Paste either format. We never invent a fake size like 273/61R20. Metric snaps to 10 mm widths and real aspect ratios; flotation snaps to sizes actually sold (33x12.50, 35x12.50, and so on).

How to read the result

The exact conversion is the truth. The nearest commercial size is a shopping hint. If the diameter delta is more than a couple of tenths of an inch, it is not a silent substitute — run it through Tire size comparison.

What this does not calculate

The commercial list is common LT/flotation and metric sizes, not every rare size ever molded. Always read the new size’s load and speed ratings.

Does not mean the converted size is in stock or legal for your GVWR.

Questions

Why isn’t there a perfect 35" metric equivalent?
Metric sizes jump in 10 mm of width and 5 points of aspect. 315/60R20 is typically the closest to 35x12.50R20 — about 0.1" shorter, not identical.
Can I mix flotation and metric on the same axle?
Only if diameter and load capacity match closely. Mixing constructions (LT vs P-metric) also changes how they carry load.

Related tools

Estimate — not a fitment approval.

Tire Size Converter — Metric/Inches