305/45R20 tire size
305/45R20 in inches: 30.81" overall diameter — 12.01" wide, 5.40" sidewall.
Overall diameter 30.81 in 782.5 mm
Section width 12.01 in 305 mm
Sidewall height 5.40 in 137.25 mm
Revs / mile 655 speedo calibration
Full dimensions
| Measurement | Metric | Imperial |
|---|---|---|
| Overall diameter | 782.5 mm | 30.81 in |
| Section width | 305 mm | 12.01 in |
| Sidewall height | 137.25 mm | 5.40 in |
| Rim diameter | 508 mm | 20 in |
| Circumference | 2458.3 mm | 96.78 in |
| Revolutions per mile | 654.7 | |
| Aspect ratio | 45% | |
Compare 305/45R20 to similar sizes
Frequently asked questions
What is the overall diameter of a 305/45R20 tire?
A 305/45R20 tire has an overall diameter of 30.81 inches (782.5 mm).
How tall is a 305/45R20 tire?
The sidewall height is 137.25 mm (5.40 inches), and the overall diameter from the ground to the top of the tire is 30.81 inches.
How many revolutions per mile does a 305/45R20 tire make?
A 305/45R20 tire makes approximately 655 revolutions per mile. Your speedometer is calibrated to this number.
What rim size does a 305/45R20 tire fit?
A 305/45R20 tire is designed for a 20-inch rim (508 mm).
All dimensions calculated using standard ETRTO formulas. Always confirm fitment with your vehicle's door-placard and a qualified tire professional before purchasing.