Metric tire size
275/65R18 tire size
A 275/65R18 tire is 32.1 inches (815 mm) tall and 10.8 in wide, for a 18-inch wheel, with a 7.0 in sidewall. That is the nominal size worked out from the code. Makers publish 32–32.4 in for real 275/65R18 tires (6 makers).
Compare 275/65R18 with other sizes
Set up for: comparing 275/65R18 with a size you're considering · Different situation?
Your current size
e.g. 265/70R17, 2657017 or 33x12.50R20
Where do I find my size?
It's on the tire sidewall, e.g. P265/70R17 115T, and on the tire placard sticker on the driver's door jamb (also in the owner's manual). The placard shows the size the vehicle came with; the sidewall shows what is fitted now. If they differ, use the placard as your starting point. Digits are enough here: 2657017 or 33125020.
Size you're considering
Real 275/65R18 tires: published diameters
Figures from the makers' own data books. They differ from the 32.1 in calculated figure because each tread design and construction measures slightly differently.
| Maker (data book) | Published diameter | Revs per mile | Approved wheel width | Listings |
|---|---|---|---|---|
| BFGoodrich | 32.1 in | 648 | 7.5–9.5 in | 1 |
| Falken | 32.1–32.3 in | 646–660 | 7.5–9.5 in | 5 |
| Goodyear | 32.1–32.3 in | 644–651 | 7.5–9.5 in | 3 |
| Hankook | 32–32.2 in | 647–653 | 7.5–9.5 in | 7 |
| Nitto | 32.09–32.32 in | — | 7.5–9.5 in | 2 |
| Toyo | 32.1–32.4 in | 640–647 | 7.5–9.5 in | 3 |
Equivalent sizes on other wheels
Sizes that appear in the maker data books with a diameter within 3% of 275/65R18. Same diameter is only one part of fitting a different size.
| Wheel | Real sizes within 3% (closest first) |
|---|---|
| 15-inch | 32x11.50R15 , 32x9.50R15 , 33x10.50R15 |
| 16-inch | 235/85R16 , 285/70R16 , 265/75R16 |
| 17-inch | 255/75R17 , 275/70R17 , 315/60R17 |
| 18-inch | 255/70R18 , 305/60R18 , 265/65R18 |
| 20-inch | 255/60R20 , 305/50R20 , 275/55R20 |
| 22-inch | 285/45R22 , 275/45R22 , 265/50R22 |
Popular comparisons with 275/65R18
FAQ
How tall is a 275/65R18 tire?
32.1 inches (815 mm) calculated from the size code. Makers publish 32–32.4 in for real tires in this size; the difference comes from tread design and construction.
How do you work out the 275/65R18 diameter?
Sidewall = 275 mm × 65% = 178.8 mm. Diameter = 18 in wheel + 2 × 178.8 mm ÷ 25.4 = 32.07 in.
Is 275/65R18 a 32-inch tire?
It is about 32.1 in tall nominally, so it is close to 32 inches. Real tires in a size vary slightly by model; check the maker's spec sheet for the exact tire.
What sizes are equivalent to 275/65R18?
Real sizes within 3% of its diameter include 235/85R16 (−1.1%), 255/75R17 (±0.0%) and 255/60R20 (−0.1%). Equal diameter alone doesn't make a size suitable: wheel width, offset, clearance and load rating all matter.
How many revolutions per mile does a 275/65R18 make?
About 629 calculated from its unloaded diameter. Makers publish 640–660 revs per mile, measured under load (a loaded tire rolls on a slightly smaller radius), which is why published figures are higher.
Open 275/65R18 in the converter · Tire size chart · 32-inch tires