All 315/45R21 tires

315/45R21 is also written 315 45 R21, 315/45 R21, 315 45 21 or 3154521. 315 is the tread width in millimetres, 45 the aspect ratio (sidewall height as a percentage of the width), R stands for radial construction, and 21 the rim diameter in inches.

A 315/45R21 tire is about 816.9 mm (32.2 in) tall, with a sidewall of 141.8 mm.

An equivalent size is a tire whose overall diameter stays within 3% of 315/45R21, so the speedometer, gearing and wheel-well clearance stay close to what the vehicle was designed for. People look for one when 315/45R21 is scarce or expensive, or when they want a different width or rim size. An equivalent size is not an automatic swap, and we do not guarantee that it fits your vehicle: check the rim width range, make sure the load index is at least the original, and allow for possible rubbing. Add your car above and rely on the “Fits on your vehicle” label shown on each product to confirm the fit.

• 285/45R22-0.2% · 22"chevron_right
• 325/40R22+0.23% · 22"chevron_right
• 255/60R20-0.36% · 20"chevron_right
• 305/50R20-0.48% · 20"chevron_right
• 285/55R20+0.56% · 20"chevron_right
• 275/55R20-0.78% · 20"chevron_right

Sidewall 141.8 mm, overall diameter 816.9 mm (32.2 in), circumference 2566.4 mm, 389.7 revolutions per km.

Read the full guide

315/45R21 tires start at $460.74 at PMC Tire. We list 4 tires in this dimension.

It depends on the exact vehicle and trim. Add your car above to check which tires in this size fit it.

In Quebec, winter tires are mandatory from December 1 to March 15, and only tires with the three-peak mountain snowflake symbol qualify. Our guide explains how to choose. Read the full guide

We carry 315/45R21 tires from 2 brands, including Continental, Pirelli.