tireheight.com275/40R18 in inches
A 275/40R18 tire is 26.7″ tall and 10.8″ wide, and fits a 18″ wheel. In inches it is written 26.7×10.8R18.
How tall 275/40R18 tires really are
Heights published by BFGoodrich, General, Michelin and Toyo for all 11 tires in this size. Their published revolutions per mile work out to 25.9″ under load (below).
Real 275/40R18 tires measure 26.65–26.70″, against 26.66″ from the size code. They run both taller and shorter than the size code.
Published revs per mile (779–780) mean the tire rolls like a 25.9″ tire on the vehicle. Use this for speedometer calibration.
The lightest (General G-MAX RS, SL) is 8.3 lb lighter per corner than the heaviest (Michelin Primacy 3, SL).
11 tires in 275/40R18
Sort by the spec you care about.
| Load | Revs/mi | Source | |||||
|---|---|---|---|---|---|---|---|
| General G-MAX RSPerformance | SL · 99Y | 26.70 | 25.9 | 10.0 | 1,709 | 779 | Spec page |
| Michelin Pilot Sport 5Performance | XL · 103(Y) | 26.70 | 26.8 | 9.0 | 1,929 | 780 | Spec page |
| Michelin Pilot Super SportPerformance | SL · 99(Y) | 26.70 | 26.8 | 10.0 | 1,709 | 780 | Spec page |
| Toyo Proxes Sport 2Performance | XL · 103(Y) | 26.70 | 27.0 | 9.2 | 1,929 | 779 | Spec page |
| General G-MAX AS07Performance | SL · 99W | 26.70 | 27.4 | 10.0 | 1,709 | 779 | Spec page |
| Michelin Pilot Sport All-Season 4Performance | XL · 103Y | 26.70 | 27.8 | 10.0 | 1,929 | 780 | Spec page |
| Toyo Extensa HP IIPerformance | SL · 99W | 26.65 | 29.3 | 9.9 | 1,709 | 779 | Spec page |
| Toyo Proxes Sport A/SPerformance | SL · 99Y | 26.65 | 30.8 | 9.7 | 1,709 | 779 | Spec page |
| BFGoodrich g-Force COMP-2 A/S PLUSPerformance | SL · 99W | 26.65 | 30.9 | 9.0 | 1,709 | 780 | Spec page |
| Michelin Pilot Sport 4Performance | XL · 103Y | 26.70 | 32.6 | 9.5 | 1,929 | 780 | Spec page |
| Michelin Primacy 3Performance | SL · 99Y | 26.65 | 34.2 | 9.0 | 1,929 | 780 | Spec page |
Is 275/40R18 a 27-inch tire?
Yes. The size code works out to 26.66″, and the 11 tires here publish 26.65–26.70″, 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 275/40R18
A percentage, not a measurement: the sidewall is 40% as tall as the tire is wide, which is 110.0 mm or 4.33 inches.
Radial construction.
Mounts on a 18-inch wheel. Approved wheel widths run 9.0″ to 11.0″.
Each tire carries up to 1,709 lb (775 kg) at its maximum pressure.
Rated for up to 168 mph sustained.
| Specification | Inches | Metric |
|---|---|---|
| Overall diameter | 26.66 | 677 mm |
| Section width | 10.83 | 275 mm |
| Sidewall height | 4.33 | 110.0 mm |
| Circumference | 83.8 | 2,127 mm |
| Revolutions per mile (calculated, unloaded) | 756.5 | 470 per km |
| Revolutions per mile (published by manufacturers) | 779–780 | 484–485 per km |
| Approved wheel width | 9.0–11.0 | 229–279 mm |
Speedometer error after switching to 275/40R18
Questions about 275/40R18
What is 275/40R18 in inches?
26.66 inches tall, 10.83 inches wide, on a 18-inch wheel. Written in inches, that is roughly 26.7×10.8R18.
How much does a 275/40R18 tire weigh?
Between 25.9 lb and 34.2 lb for the 11 tires listed here. The lightest is the General G-MAX RS (SL); the heaviest is the Michelin Primacy 3 (SL).
What wheel width do I need for 275/40R18?
Manufacturers approve 9.0–11.0″ wide wheels for this size.
How many revolutions per mile does a 275/40R18 make?
Published figures run 779–780 revolutions per mile. The calculated figure is 756.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.
How much taller is 275/40R18 than 215/50R18?
0.20 inches taller on paper (26.66″ vs 26.46″), which raises the axle about 0.10″. Your speedometer will read about 0.7% slow.