265/40R20 tire size in inches

A 265/40R20 tire measures

28.3" tall × 10.4" wide

4.17" sidewall on a 20" wheel. 711 revolutions per mile.

265/40R20 means a tire 265 mm wide, with sidewalls 40% as tall as the tire is wide (106 mm), radial construction (R), for a 20 inch wheel.

28.3"20" rim4.2"10.4" wide
265/40R20: 28.3 inches tall, 10.4 inches wide, on a 20 inch rim, drawn to scale

265/40R20 specs

Overall diameter (height)28.35 inches (720 mm)
Section width10.43 inches (265 mm)
Sidewall height4.17 inches (106 mm)
Wheel (rim) diameter20 inches
Circumference89.1 inches (2,262 mm)
Revolutions per mile711
Revolutions per kilometer442
Approximate rim width8.5" to 10.0"
In inches (flotation style)28.3x10.4R20
Aspect ratio40%

Calculated from the size. Real tires differ by brand, model and tread depth, typically by a few tenths of an inch.

Sizes that can replace 265/40R20 on a 20" wheel

These 20" sizes are within 3% of 265/40R20's overall diameter, the range most tire shops treat as interchangeable.

SizeDiameterWidthDifferenceReal speed at 60
235/45R2028.33"9.25"−0.1%60.0 mphCompare
355/30R2028.39"13.98"+0.1%60.1 mphCompare
305/35R2028.41"12.01"+0.2%60.1 mphCompare
215/50R2028.46"8.46"+0.4%60.3 mphCompare
345/30R2028.15"13.58"−0.7%59.6 mphCompare
295/35R2028.13"11.61"−0.8%59.5 mphCompare
255/40R2028.03"10.04"−1.1%59.3 mphCompare
275/40R2028.66"10.83"+1.1%60.7 mphCompare
245/45R2028.68"9.65"+1.2%60.7 mphCompare
315/35R2028.68"12.40"+1.2%60.7 mphCompare
225/45R2027.97"8.86"−1.3%59.2 mphCompare
335/30R2027.91"13.19"−1.5%59.1 mphCompare

Same height on other wheel sizes (plus and minus sizing)

SizeWheelDiameterDifference
285/55R1616"28.34"0.0%Compare
185/85R1616"28.38"+0.1%Compare
215/55R1919"28.31"−0.1%Compare
265/35R2121"28.30"−0.2%Compare
215/85R1414"28.39"+0.2%Compare
265/45R1919"28.39"+0.2%Compare
205/70R1717"28.30"−0.2%Compare
325/25R2222"28.40"+0.2%Compare
295/40R1919"28.29"−0.2%Compare
225/70R1616"28.40"+0.2%Compare
235/40R2121"28.40"+0.2%Compare
225/75R1515"28.29"−0.2%Compare

One size up or down

Compare 265/40R20 with another size

With 275/40R20 tires, when your speedometer says 60 mph you are really going

60.7 mph

275/40R20 is +0.31 inches (+1.1%) in overall diameter. That is within the 3% most shops and makers allow.

265/40R20275/40R20Difference%
Overall diameter28.35"28.66"+0.31"+1.1%
Section width10.43"10.83"+0.39"+3.8%
Sidewall height4.17"4.33"+0.16"+3.8%
Circumference89.05"90.04"+0.99"+1.1%
Revolutions per mile711.5703.7−7.8−1.1%

Questions

How tall is a 265/40R20 tire?
A 265/40R20 tire is 28.3 inches tall (720 mm), calculated from the size. It is 10.4 inches wide with 4.2 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
What does 265/40R20 mean?
265/40R20 means a tire 265 mm wide, with sidewalls 40% as tall as the tire is wide (106 mm), radial construction (R), for a 20 inch wheel.
How many revolutions per mile does a 265/40R20 tire make?
About 711 revolutions per mile, based on a circumference of 89.1 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
What rim width fits a 265/40R20 tire?
Roughly 8.5" to 10.0". Check the tire maker's approved rim range for the exact model before buying wheels.
Can I use 235/45R20 instead of 265/40R20?
235/45R20 is −0.02 inches (−0.1%) in overall diameter, so at an indicated 60 mph you would be doing 60.0 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.

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