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Tire size

265/40R21 tire size: dimensions explained

Factory size on the Porsche Macan (gas, 95B). 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 width265 mm10.43 in
Sidewall height106 mm4.17 in
Overall diameter745.4 mm29.35 in
Wheel diameter533.4 mm21 in
Circumference2342 mm92.2 in
Revolutions per mile687

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

Reading the marking

265 is the section width in millimetres, 40 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 265/40R21 with another size →

265/40R21 tires at Tire Rack

All-season

TireLoad/speedPrice per tire
Advanta HPZ-02
Ultra High Performance All-Season		XL 105V$173.12View at Tire Rack
Toyo Celsius Sport
Grand Touring All-Season		XL 105Y$387.83View at Tire Rack

Highway / touring

TireLoad/speedPrice per tire
Kumho Crugen GT Pro
Crossover/SUV Touring All-Season		XL 105W$236.73View at Tire Rack
Firestone Destination LE4
Highway All-Season		XL 105V$271.99View at Tire Rack

Summer performance

TireLoad/speedPrice per tire
Pirelli P Zero (PZ4)
Max Performance Summer		XL 105H$135.46View at Tire Rack
Continental ContiSportContact 5P
Max Performance Summer		101Y$287.29View at Tire Rack

Winter

TireLoad/speedPrice per tire
Vredestein Wintrac Pro+
Performance Winter / Snow		XL 105Y$300.53View at Tire Rack
Bridgestone Blizzak IcePeak
Studless Ice & Snow		XL 105T$415.99View at Tire Rack

Showing the lowest-priced in-stock options in each category from 43 265/40R21 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