265/65R18 designates a tire 265 mm (10.4") wide with a sidewall 65% as tall as it is wide — about 172 mm (6.8") — mounted on a 18-inch wheel. That works out to an overall diameter of roughly 31.6", a circumference of about 99.2", and approximately 639 revolutions per mile. Exact figures vary slightly by manufacturer and tread design.
Of the 85 265/65R18 tire models we track, the most common category is all-terrain (43 models), followed by highway all-season truck (26) — a good indicator of the kind of vehicles and driving this size is designed for.