tireheight.com315/30R20 in inches
A 315/30R20 tire is 27.4″ tall and 12.4″ wide, and fits a 20″ wheel. In inches it is written 27.4×12.4R20.
How tall 315/30R20 tires really are
Heights published by Michelin and Toyo for all 9 tires in this size. Their published revolutions per mile work out to 26.6–26.7″ under load (below).
Real 315/30R20 tires measure 27.48–27.50″, against 27.44″ from the size code. Every one runs taller than the size code.
Published revs per mile (756–757) mean the tire rolls like a 26.6–26.7″ tire on the vehicle. Use this for speedometer calibration.
The lightest (Michelin Pilot Sport Cup 2 R, XL) is 8.0 lb lighter per corner than the heaviest (Toyo Proxes R888R, SL).
9 tires in 315/30R20
Sort by the spec you care about.
| Load | Revs/mi | Source | |||||
|---|---|---|---|---|---|---|---|
| Michelin Pilot Sport Cup 2 RPerformance | XL · 104(Y) | 27.50 | 27.1 | 5.5 | 1,984 | 757 | Spec page |
| Michelin Pilot Sport Cup 2Performance | XL · 104(Y) | 27.50 | 30.4 | 5.5 | 1,984 | 757 | Spec page |
| Michelin Pilot Sport Cup 2Performance | XL · 104(Y) | 27.50 | 30.6 | 7.2 | 1,984 | 757 | Spec page |
| Michelin Pilot Sport Cup 2 RPerformance | SL · 101(Y) | 27.50 | 30.6 | 5.5 | 1,819 | 757 | Spec page |
| Toyo Proxes RPerformance | SL · 101(Y) | 27.50 | 30.6 | 3.7 | 1,819 | 756 | Spec page |
| Toyo Proxes RRPerformance | SL · (101Y) | 27.48 | 32.6 | 3.6 | 1,819 | 756 | Spec page |
| Michelin Pilot Sport 4 SPerformance | XL · 104(Y) | 27.50 | 32.7 | 8.5 | 1,984 | 757 | Spec page |
| Michelin Pilot Sport 4 SPerformance | XL · 104(Y) | 27.50 | 33.0 | 8.5 | 1,984 | 757 | Spec page |
| Toyo Proxes R888RPerformance | SL · 101(Y) | 27.48 | 35.1 | 6.3 | 1,819 | 756 | Spec page |
Is 315/30R20 a 27-inch tire?
Close. The size code works out to 27.44″, and the 9 tires here publish 27.48–27.50″, so people call it a 27.
All 27-inch tire sizes, on every wheel size.
Compare with nearby sizes
Differences in overall diameter, calculated from each size code.
How to read 315/30R20
A percentage, not a measurement: the sidewall is 30% as tall as the tire is wide, which is 94.5 mm or 3.72 inches.
Radial construction.
Mounts on a 20-inch wheel. Approved wheel widths run 10.5″ to 11.5″.
Each tire carries up to 1,984 lb (900 kg) at its maximum pressure.
Rated for up to 186 mph sustained.
Printed after the size. In this size the XL tires carry up to 1,984 lb each and the standard-load tires up to 1,819 lb, as published.
| Specification | Inches | Metric |
|---|---|---|
| Overall diameter | 27.44 | 697 mm |
| Section width | 12.40 | 315 mm |
| Sidewall height | 3.72 | 94.5 mm |
| Circumference | 86.2 | 2,190 mm |
| Revolutions per mile (calculated, unloaded) | 735.0 | 457 per km |
| Revolutions per mile (published by manufacturers) | 756–757 | 470 per km |
| Approved wheel width | 10.5–11.5 | 267–292 mm |
Speedometer error after switching to 315/30R20
Questions about 315/30R20
What is 315/30R20 in inches?
27.44 inches tall, 12.40 inches wide, on a 20-inch wheel. Written in inches, that is roughly 27.4×12.4R20.
How much does a 315/30R20 tire weigh?
Between 27.1 lb and 35.1 lb for the 9 tires listed here. The lightest is the Michelin Pilot Sport Cup 2 R (XL); the heaviest is the Toyo Proxes R888R (SL).
What wheel width do I need for 315/30R20?
Manufacturers approve 10.5–11.5″ wide wheels for this size.
How many revolutions per mile does a 315/30R20 make?
Published figures run 756–757 revolutions per mile. The calculated figure is 735.0, but manufacturers measure the tire under load, where it rolls on a smaller radius.
How much taller is 315/30R20 than 235/40R20?
0.04 inches taller on paper (27.44″ vs 27.40″), which raises the axle about 0.02″. Your speedometer will read about 0.1% slow.