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Best 315/70 R18 tires

2 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Toyo Open Country M/T at 90/100.

35.4″
overall diameter
12.4″
section width
18″
rim diameter
570.3
revs per mile

Best 315/70 R18 mud-terrain tires

2
Conversion

315/70 R18 in inches

Overall diameter35.4″
Section width12.4″
Rim diameter18″
Sidewall height221 mm
Circumference111.1″
Revolutions per mile570.3

The closest flotation size is 35x12.50R18 — 1% shorter and 0.8% wider. Compare them in the calculator.

Wheels

What rims fit 315/70 R18 tires?

A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.

Minimum
8.5″
Ideal
10″
Maximum
11″

Rim diameter is fixed at 18″ — only the width varies. Estimated from the 12.4″ section width (70–90% rule).

Sidewall

315/70 R18 — what does it mean?

ParameterMeaning
315The first number is the section width — 315 mm, or about 12.4 inches across the widest part of the tire.
70The second number is the aspect ratio: sidewall height as a percentage of width. At 70%, the sidewall is about 221 mm tall.
R18R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 18-inch wheel.