tireheight.com215/40R18 in inches
A 215/40R18 tire is 24.8″ tall and 8.5″ wide, and fits a 18″ wheel. In inches it is written 24.8×8.5R18.
How tall 215/40R18 tires really are
Heights published by General, Michelin and Toyo for all 7 tires in this size. Their published revolutions per mile work out to 24.0–24.2″ under load (below).
Real 215/40R18 tires measure 24.76–25.00″, against 24.77″ from the size code. Most run taller than the size code (6 of 7).
- Michelin Pilot Sport All-Season 425.00″ +0.23″
- General G-MAX AS0724.80″ +0.03″
- Michelin Pilot Sport 424.80″ +0.03″
- Michelin Pilot Sport 524.80″ +0.03″
- Michelin Pilot Sport Cup 2 Connect24.80″ +0.03″
- Toyo Proxes Sport 224.80″ +0.03″
- Toyo Proxes Sport A/S24.76″ −0.01″
Published revs per mile (832–840) mean the tire rolls like a 24.0–24.2″ tire on the vehicle. Use this for speedometer calibration.
The lightest (Michelin Pilot Sport Cup 2 Connect, XL) is 3.3 lb lighter per corner than the heaviest (Toyo Proxes Sport A/S, XL).
7 tires in 215/40R18
Sort by the spec you care about.
| Load | Revs/mi | Source | |||||
|---|---|---|---|---|---|---|---|
| Michelin Pilot Sport Cup 2 ConnectPerformance | XL · 89(Y) | 24.80 | 19.0 | 7.2 | 1,279 | 840 | Spec page |
| Michelin Pilot Sport 4Performance | SL · 85Y | 24.80 | 20.1 | 9.5 | 1,135 | 840 | Spec page |
| Toyo Proxes Sport 2Performance | XL · 89Y | 24.80 | 20.1 | 8.8 | 1,279 | 839 | Spec page |
| General G-MAX AS07Performance | XL · 89W | 24.80 | 20.2 | 10.0 | 1,279 | 839 | Spec page |
| Michelin Pilot Sport 5Performance | XL · 89(Y) | 24.80 | 20.2 | 9.0 | 1,279 | 840 | Spec page |
| Michelin Pilot Sport All-Season 4Performance | XL · 89Y | 25.00 | 21.5 | 10.0 | 1,279 | 832 | Spec page |
| Toyo Proxes Sport A/SPerformance | XL · 89Y | 24.76 | 22.3 | 9.3 | 1,279 | 839 | Spec page |
Is 215/40R18 a 25-inch tire?
Yes. The size code works out to 24.77″, and the 7 tires here publish 24.76–25.00″, so people call it a 25.
Compare with nearby sizes
Differences in overall diameter, calculated from each size code.
How to read 215/40R18
A percentage, not a measurement: the sidewall is 40% as tall as the tire is wide, which is 86.0 mm or 3.39 inches.
Radial construction.
Mounts on a 18-inch wheel. Approved wheel widths run 7.0″ to 8.5″.
Each tire carries up to 1,279 lb (580 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 1,279 lb each and the standard-load tires up to 1,135 lb, as published.
| Specification | Inches | Metric |
|---|---|---|
| Overall diameter | 24.77 | 629 mm |
| Section width | 8.46 | 215 mm |
| Sidewall height | 3.39 | 86.0 mm |
| Circumference | 77.8 | 1,977 mm |
| Revolutions per mile (calculated, unloaded) | 814.2 | 506 per km |
| Revolutions per mile (published by manufacturers) | 832–840 | 517–522 per km |
| Approved wheel width | 7.0–8.5 | 178–216 mm |
Speedometer error after switching to 215/40R18
Questions about 215/40R18
What is 215/40R18 in inches?
24.77 inches tall, 8.46 inches wide, on a 18-inch wheel. Written in inches, that is roughly 24.8×8.5R18.
How much does a 215/40R18 tire weigh?
Between 19.0 lb and 22.3 lb for the 7 tires listed here. The lightest is the Michelin Pilot Sport Cup 2 Connect (XL); the heaviest is the Toyo Proxes Sport A/S (XL).
What wheel width do I need for 215/40R18?
Manufacturers approve 7.0–8.5″ wide wheels for this size.
How many revolutions per mile does a 215/40R18 make?
Published figures run 832–840 revolutions per mile. The calculated figure is 814.2, but manufacturers measure the tire under load, where it rolls on a smaller radius.
How much taller is 215/40R18 than 245/35R18?
0.02 inches taller on paper (24.77″ vs 24.75″), which raises the axle about 0.01″. Your speedometer will read about 0.1% slow.