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Tire size

345/25R21 tire size: dimensions explained

Factory size on the Chevrolet Corvette (C8). 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 width345 mm13.58 in
Sidewall height86.3 mm3.4 in
Overall diameter705.9 mm27.79 in
Wheel diameter533.4 mm21 in
Circumference2217 mm87.3 in
Revolutions per mile726

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

Reading the marking

345 is the section width in millimetres, 25 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.

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345/25R21 tires at Tire Rack

Tire Rack's feed had no in-stock 345/25R21 tires as of Nov 7, 2026, 9:19 PM PT.

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