What 285/70R17 means
The inputs are 285 mm nominal section width, a 70-percent aspect ratio, and a 17-inch nominal rim diameter. The R identifies radial construction. The width is not a wheel-width measurement, and the rim number is not the outside diameter of the tire.
Nominal sidewall height is 285 × 70 ÷ 100 = 199.5 mm. Adding two sidewalls to the 431.8 mm rim gives 830.8 mm (32.71 in) of nominal outside diameter.
A calculated reference
The source entry is LT285/70 R 17, and the LT prefix is retained in the evidence record. At 70 percent, its 285 mm nominal width gives a 199.5 mm sidewall. Compared with 265/70R17, width grows by 20 mm while full diameter grows by 28 mm. No load equivalence follows from these geometric differences.
Using a perfect-circle model, circumference is 2610.04 mm, equivalent to 383.14 revolutions per kilometer or 616.6 per mile. These are derived from unrounded diameter; actual rolling circumference also depends on the product and operating conditions.
Source and scope
General Tire’s Grabber A/TX source includes LT285/70 R 17, article 04507250000. It was checked on October 27, 2026. That record verifies the published marking used here; it does not turn these calculated dimensions into that product’s measured specification or establish availability. The LT prefix is preserved in the source record. This page does not calculate load capacity or remove that designation’s significance.
Use the exact product and vehicle requirements for load and speed ratings, permitted rim dimensions, inflation and clearance. Nominal geometry alone cannot verify fitment, braking behavior, handling or safety.
Sources and further reading
- Grabber A/TX — Specifications — General Tire
- Tire Markings Explained — Michelin
- Tire glossary — Michelin