What 215/65R16 means
The inputs are 215 mm nominal section width, a 65-percent aspect ratio, and a 16-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 215 × 65 ÷ 100 = 139.75 mm. Adding two sidewalls to the 406.4 mm rim gives 685.9 mm (27 in) of nominal outside diameter.
A calculated reference
The 139.75 mm sidewall illustrates why display rounding should happen after the calculation. Two sidewalls total 279.5 mm exactly in this model; rounding each one first would change the computed diameter.
Using a perfect-circle model, circumference is 2154.82 mm, equivalent to 464.08 revolutions per kilometer or 746.86 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 AltiMAX RT45 source includes 215/65R16, article 15576320000. 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.
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
- AltiMAX RT45 — General Tire
- Tire Markings Explained — Michelin
- Tire glossary — Michelin