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Tire size

275/65R18 tire size: dimensions explained

Factory size on the Ford F-150, Ram 1500. 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 height178.8 mm7.04 in
Overall diameter814.7 mm32.07 in
Wheel diameter457.2 mm18 in
Circumference2560 mm100.8 in
Revolutions per mile629

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, 65 is the sidewall height as a percentage of that width, R means radial construction, and 18 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 275/65R18 with another size →

275/65R18 tires at Tire Rack

All-season

TireLoad/speedPrice per tire
Radar Dimax AS-8
Grand Touring All-Season		116H$174.22View at Tire Rack
Cooper ProControl
Grand Touring All-Season		116T$235.99View at Tire Rack

Highway / touring

TireLoad/speedPrice per tire
Advanta SVT-01
Crossover/SUV Touring All-Season		114H$167.86View at Tire Rack
Laufenn X FIT HT
Highway All-Season		116T$171.99View at Tire Rack

All-terrain

TireLoad/speedPrice per tire
Advanta ATX-850
Off-Road All-Terrain Truck		116T$180.45View at Tire Rack
Radar Renegade A/T Pro
On-Road All-Terrain		XL 116T$184.77View at Tire Rack

Winter

TireLoad/speedPrice per tire
Firestone Winterforce 2 UV
Light Truck/SUV Studdable Snow Truck		114S$217.99View at Tire Rack
General Grabber Arctic X
Light Truck/SUV Studdable Snow Truck		XL 116T$232.99View at Tire Rack

Rugged / mud-terrain

TireLoad/speedPrice per tire
Radar Renegade R/T
Rugged All-Terrain		E 123/120Q$241.25View at Tire Rack
Cooper Discoverer Rugged Trek
Rugged All-Terrain		116T$298.99View at Tire Rack

Showing the lowest-priced in-stock options in each category from 146 275/65R18 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