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Tire size

275/55R21 tire size: dimensions explained

Factory size on the Rivian R1T, Rivian R1S. Below are the dimensions calculated from the size marking itself. Your vehicle's correct size, load index and speed rating are on the placard in the driver's door jamb; check it before buying.

MeasurementMetricImperial
Section width275 mm10.83 in
Sidewall height151.3 mm5.95 in
Overall diameter835.9 mm32.91 in
Wheel diameter533.4 mm21 in
Circumference2626 mm103.4 in
Revolutions per mile613

Calculated values: diameter = wheel + 2 × (width × aspect ratio). Real tires vary slightly by brand and model.

Reading the marking

275 is the section width in millimetres, 55 is the sidewall height as a percentage of that width, R means radial construction, and 21 is the wheel diameter in inches. A passenger (P or Euro-metric) tire and an LT tire in the same size are not interchangeable without checking load requirements.

Compare 275/55R21 with another size →

275/55R21 tires at Tire Rack

Highway / touring

TireLoad/speedPrice per tire
Hankook iON HT
Highway All-Season		XL 116H$295.99View at Tire Rack
Yokohama Geolandar H/T4
Highway All-Season		XL 116H$349.99View at Tire Rack

All-terrain

TireLoad/speedPrice per tire
Yokohama Geolandar A/T4
On-Road All-Terrain		XL 116H$455.99View at Tire Rack

Showing the lowest-priced in-stock options in each category from 6 275/55R21 tires in Tire Rack's feed, sorted by price only. We don't rank by commission. Match or exceed the load index and speed rating on your placard.

Affiliate links: if you buy through a Tire Rack link, RightTread may earn a commission through CJ. It doesn't change your price. Prices are Tire Rack's per-tire prices from Tire Rack's product feed as of Nov 7, 2026, 9:19 PM PT. Prices change, so confirm on Tire Rack before you buy. Disclosure

Other sizes