CarSpecsHQ

315/35R18 tire size

315/35R18 is a metric size: 26.7" tall, 12.4" wide, on a 18" rim — about a 26.5x12.50R18. The sidewall is 4.3" and the tire turns 756 times per mile.

Diameter 26.7" sidewall 4.34" 18" rim width 315 mm (12.4")
315/35R18: 315 mm wide, sidewall 35% of the width (4.34"), on a 18" rim → 26.68" tall.

315/35R18 specs

Overall diameter (height)26.68" · 678 mm
Section width12.40" · 315 mm
Sidewall height4.34" · 110 mm (35% of width)
Rim diameter18"
Circumference83.82" · 2.129 m
Revolutions per mile756 (470 per km)
Inch (flotation) equivalent26.5x12.50R18

Equivalent sizes on a 18" rim

Sizes within ±5% of the overall diameter. Green rows are inside the usual ±3% limit for keeping the speedometer, ABS and gearing right; red rows are bigger changes that need clearance checks.

SizeDiameterDifferenceWidthSpeedo at 60
225/45R18 common25.97"-2.66%-90 mm58.4 mphcalculate →
245/40R18 common25.72"-3.62%-70 mm57.8 mphcalculate →
245/45R18 common26.68"0.00%-70 mm60.0 mphcalculate →
235/50R18 common27.25"+2.14%-80 mm61.3 mphcalculate →
235/45R18 common26.33"-1.33%-80 mm59.2 mphcalculate →
235/40R18 common25.40"-4.80%-80 mm57.1 mphcalculate →
225/50R18 common26.86"+0.66%-90 mm60.4 mphcalculate →
225/55R18 common27.74"+3.98%-90 mm62.4 mphcalculate →
255/40R18 common26.03"-2.43%-60 mm58.5 mphcalculate →
245/50R18 common27.65"+3.62%-70 mm62.2 mphcalculate →
275/35R18 common25.58"-4.13%-40 mm57.5 mphcalculate →
255/45R18 common27.04"+1.33%-60 mm60.8 mphcalculate →
215/55R18 common27.31"+2.36%-100 mm61.4 mphcalculate →
275/40R18 common26.66"-0.07%-40 mm60.0 mphcalculate →
215/45R18 common25.62"-3.98%-100 mm57.6 mphcalculate →
265/40R1826.35"-1.25%-50 mm59.2 mphcalculate →
285/35R1825.85"-3.10%-30 mm58.1 mphcalculate →
315/30R1825.44"-4.65%0 mm57.2 mphcalculate →
295/35R1826.13"-2.07%-20 mm58.8 mphcalculate →
335/30R1825.91"-2.88%+20 mm58.3 mphcalculate →
275/45R1827.74"+3.98%-40 mm62.4 mphcalculate →
215/50R1826.46"-0.81%-100 mm59.5 mphcalculate →
295/40R1827.29"+2.29%-20 mm61.4 mphcalculate →
265/45R1827.39"+2.66%-50 mm61.6 mphcalculate →
285/40R1826.98"+1.11%-30 mm60.7 mphcalculate →
305/35R1826.41"-1.03%-10 mm59.4 mphcalculate →
345/35R1827.51"+3.10%+30 mm61.9 mphcalculate →
315/40R1827.92"+4.65%0 mm62.8 mphcalculate →
305/40R1827.61"+3.47%-10 mm62.1 mphcalculate →
155/70R1826.54"-0.52%-160 mm59.7 mphcalculate →
325/35R1826.96"+1.03%+10 mm60.6 mphcalculate →
165/70R1827.09"+1.55%-150 mm60.9 mphcalculate →
145/80R1827.13"+1.70%-170 mm61.0 mphcalculate →
26x12.00R1826.00"-2.55%-10 mm58.5 mphcalculate →
26x6.00R1826.00"-2.55%-163 mm58.5 mphcalculate →
26x8.00R1826.00"-2.55%-112 mm58.5 mphcalculate →
145/70R1825.99"-2.58%-170 mm58.5 mphcalculate →
145/85R1827.70"+3.84%-170 mm62.3 mphcalculate →
28x12.00R1828.00"+4.94%-10 mm63.0 mphcalculate →
195/60R1827.21"+1.99%-120 mm61.2 mphcalculate →
345/30R1826.15"-1.99%+30 mm58.8 mphcalculate →
205/60R1827.69"+3.76%-110 mm62.3 mphcalculate →
28x10.00R1828.00"+4.94%-61 mm63.0 mphcalculate →

Plus / minus sizing: 17" and 19" rims

Same overall height on a different rim. Check wheel width and clearance before switching.

SizeDiameterDifferenceWidthSpeedo at 60
225/55R17 common26.74"+0.24%-90 mm60.1 mphcalculate →
245/40R19 common26.72"+0.13%-70 mm60.1 mphcalculate →
275/35R19 common26.58"-0.38%-40 mm59.8 mphcalculate →
285/35R19 common26.85"+0.65%-30 mm60.4 mphcalculate →
325/30R1926.68"-0.01%+10 mm60.0 mphcalculate →
245/50R1726.65"-0.13%-70 mm59.9 mphcalculate →
315/30R1926.44"-0.90%0 mm59.5 mphcalculate →
195/50R1926.68"-0.01%-120 mm60.0 mphcalculate →
155/80R1726.76"+0.31%-160 mm60.2 mphcalculate →
335/30R1926.91"+0.87%+20 mm60.5 mphcalculate →
205/60R1726.69"+0.01%-110 mm60.0 mphcalculate →

Try another size against 315/35R18

Questions

What size is 315/35R18 in inches?

315/35R18 is about 26.7" tall and 12.4" wide on a 18-inch rim — roughly a 26.5x12.50R18 in inch sizing.

What does 315/35R18 mean?

315 mm section width, sidewall 35% of the width (4.34"), radial construction, 18-inch rim.

What tire sizes are equivalent to 315/35R18?

On the same 18" rim, within 3% of the diameter: 245/45R18 (0.00%), 275/40R18 (-0.07%), 155/70R18 (-0.52%), 225/50R18 (+0.66%), 215/50R18 (-0.81%), 305/35R18 (-1.03%).

How many revolutions per mile does a 315/35R18 tire make?

About 756 revolutions per mile (circumference 83.8").

How these numbers are computed

Diameter = rim + 2 × sidewall, sidewall = width × aspect ÷ 100, circumference = π × diameter, revolutions per mile = 63,360 ÷ circumference. Real tires differ by brand by a few tenths of an inch. Last reviewed October 14, 2026.