235/70R15 designates a tire 235 mm (9.3") wide with a sidewall 70% as tall as it is wide — about 165 mm (6.5") — mounted on a 15-inch wheel. That works out to an overall diameter of roughly 28.0", a circumference of about 87.8", and approximately 722 revolutions per mile. Exact figures vary slightly by manufacturer and tread design.
Of the 14 235/70R15 tire models we track, the most common category is highway all-season truck (4 models), followed by grand touring all-season (4) — a good indicator of the kind of vehicles and driving this size is designed for.