CarSpecsHQ

265/45R18 tire size

265/45R18 is a metric size: 27.4" tall, 10.4" wide, on a 18" rim — about a 27.5x10.50R18. The sidewall is 4.7" and the tire turns 736 times per mile.

Diameter 27.4" sidewall 4.69" 18" rim width 265 mm (10.4")
265/45R18: 265 mm wide, sidewall 45% of the width (4.69"), on a 18" rim → 27.39" tall.

265/45R18 specs

Overall diameter (height)27.39" · 696 mm
Section width10.43" · 265 mm
Sidewall height4.69" · 119 mm (45% of width)
Rim diameter18"
Circumference86.05" · 2.186 m
Revolutions per mile736 (458 per km)
Inch (flotation) equivalent27.5x10.50R18

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
245/45R18 common26.68"-2.59%-20 mm58.4 mphcompare →
235/50R18 common27.25"-0.50%-30 mm59.7 mphcompare →
235/55R18 common28.18"+2.87%-30 mm61.7 mphcompare →
235/45R18 common26.33"-3.88%-30 mm57.7 mphcompare →
225/60R18 common28.63"+4.53%-40 mm62.7 mphcompare →
225/50R18 common26.86"-1.94%-40 mm58.8 mphcompare →
225/55R18 common27.74"+1.29%-40 mm60.8 mphcompare →
255/40R18 common26.03"-4.96%-10 mm57.0 mphcompare →
245/50R18 common27.65"+0.93%-20 mm60.6 mphcompare →
255/45R18 common27.04"-1.29%-10 mm59.2 mphcompare →
215/55R18 common27.31"-0.29%-50 mm59.8 mphcompare →
275/40R18 common26.66"-2.66%+10 mm58.4 mphcompare →
245/55R1828.61"+4.46%-20 mm62.7 mphcompare →
265/40R1826.35"-3.81%0 mm57.7 mphcompare →
295/35R1826.13"-4.60%+30 mm57.2 mphcompare →
275/45R1827.74"+1.29%+10 mm60.8 mphcompare →
215/50R1826.46"-3.38%-50 mm58.0 mphcompare →
295/40R1827.29"-0.36%+30 mm59.8 mphcompare →
285/40R1826.98"-1.51%+20 mm59.1 mphcalculate →
345/35R1827.51"+0.43%+80 mm60.3 mphcalculate →
305/35R1826.41"-3.59%+40 mm57.8 mphcalculate →
295/45R1828.45"+3.88%+30 mm62.3 mphcalculate →
255/50R1828.04"+2.37%-10 mm61.4 mphcalculate →
315/40R1827.92"+1.94%+50 mm61.2 mphcalculate →
305/40R1827.61"+0.79%+40 mm60.5 mphcalculate →
215/60R1828.16"+2.80%-50 mm61.7 mphcalculate →
155/85R1828.37"+3.59%-110 mm62.2 mphcalculate →
145/80R1827.13"-0.93%-120 mm59.4 mphcalculate →
165/70R1827.09"-1.08%-100 mm59.4 mphcalculate →
145/85R1827.70"+1.15%-120 mm60.7 mphcalculate →
325/35R1826.96"-1.58%+60 mm59.1 mphcalculate →
28x12.00R1828.00"+2.23%+40 mm61.3 mphcalculate →
285/45R1828.10"+2.59%+20 mm61.6 mphcalculate →
155/70R1826.54"-3.09%-110 mm58.1 mphcalculate →
195/60R1827.21"-0.65%-70 mm59.6 mphcalculate →
205/60R1827.69"+1.08%-60 mm60.6 mphcalculate →
28x10.00R1828.00"+2.23%-11 mm61.3 mphcalculate →
315/35R1826.68"-2.59%+50 mm58.4 mphcalculate →
265/50R1828.43"+3.81%0 mm62.3 mphcalculate →
345/30R1826.15"-4.53%+80 mm57.3 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
235/55R17 common27.18"-0.78%-30 mm59.5 mphcompare →
225/60R17 common27.63"+0.88%-40 mm60.5 mphcompare →
275/40R19 common27.66"+0.99%+10 mm60.6 mphcompare →
215/60R17 common27.16"-0.85%-50 mm59.5 mphcompare →
235/45R19 common27.33"-0.23%-30 mm59.9 mphcompare →
265/40R1927.35"-0.16%0 mm59.9 mphcompare →
295/35R1927.13"-0.95%+30 mm59.4 mphcompare →
345/30R1927.15"-0.88%+80 mm59.5 mphcompare →
245/55R1727.61"+0.80%-20 mm60.5 mphcalculate →
305/35R1927.41"+0.06%+40 mm60.0 mphcalculate →
155/70R1927.54"+0.56%-110 mm60.3 mphcalculate →
355/30R1927.39"-0.01%+90 mm60.0 mphcalculate →
165/80R1727.39"+0.01%-100 mm60.0 mphcalculate →
215/50R1927.46"+0.27%-50 mm60.2 mphcalculate →
175/60R1927.27"-0.45%-90 mm59.7 mphcalculate →
145/90R1727.28"-0.42%-120 mm59.7 mphcalculate →
205/65R1727.49"+0.37%-60 mm60.2 mphcalculate →

Try another size against 265/45R18

Questions

What size is 265/45R18 in inches?

265/45R18 is about 27.4" tall and 10.4" wide on a 18-inch rim — roughly a 27.5x10.50R18 in inch sizing.

What does 265/45R18 mean?

265 mm section width, sidewall 45% of the width (4.69"), radial construction, 18-inch rim.

What tire sizes are equivalent to 265/45R18?

On the same 18" rim, within 3% of the diameter: 215/55R18 (-0.29%), 295/40R18 (-0.36%), 345/35R18 (+0.43%), 235/50R18 (-0.50%), 195/60R18 (-0.65%), 305/40R18 (+0.79%).

How many revolutions per mile does a 265/45R18 tire make?

About 736 revolutions per mile (circumference 86.0").

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.