2021 Lexus RX tire size

Most common factory size

P235/55R20

Tire sizes by trim

Source marks: one source

2021 Lexus RX tire size by trim
Size	Trims	Width, mm	Sidewall, % of width	Rim, in	Diameter, in	Sidewall, in	Revs per mile
P235/55R20	350 F Sport FWD, 350 F Sport AWD, 350 F Sport Handling FWD, RX 450h F SPORT SUV 4D AWD, 350 F Sport Handling AWD, RX 450h F SPORT Handling AWD +3 more	235	55	20	30.18	5.09	668
P235/65R18	350 FWD, 350 AWD, RX 450h AWD, 350L FWD, 350L AWD, RX 450hL AWD	235	65	18	30.03	6.01	672

What P235/55R20 means
Part	Number	Meaning
Type	P	Passenger car tire.
Width	235 mm	Tread width. 9.3 in.
Sidewall	55	Sidewall height is 55% of the width.
Construction	R	Radial tire.
Rim	20 in	Fits 20 in wheels.

Within 3% of the stock diameter. A common shop guideline, not a maker spec.

Sizes within 3% of P235/55R20
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
235/50R21	21	30.25	+0.2%	59.9 mph
235/60R19	19	30.10	-0.2%	60.1 mph
285/45R20	20	30.10	-0.3%	60.2 mph
295/40R21	21	30.29	+0.4%	59.8 mph
255/55R19	19	30.04	-0.4%	60.3 mph
255/50R20	20	30.04	-0.5%	60.3 mph
255/45R21	21	30.04	-0.5%	60.3 mph
285/40R21	21	29.98	-0.7%	60.4 mph

Sizes within 3% of P235/65R18
Size	Rim, in	Diameter, in	Change	Speedo reads at 60 mph
255/55R19	19	30.04	+0.1%	60.0 mph
255/60R18	18	30.05	+0.1%	60.0 mph
255/65R17	17	30.05	+0.1%	60.0 mph
235/60R19	19	30.10	+0.2%	59.9 mph
235/70R17	17	29.95	-0.2%	60.1 mph
275/55R18	18	29.91	-0.4%	60.2 mph
275/50R19	19	29.83	-0.7%	60.4 mph
225/60R19	19	29.63	-1.3%	60.8 mph

Checked against 292 factory sizes listed for 2009-2027 US models.

Tire pressure is on the driver door sticker. Not in this data.

Optional wheel packages may differ.