Metric tire size

285/75R18 tire size

A 285/75R18 tire is 34.8 inches (885 mm) tall and 11.2 in wide, for a 18-inch wheel, with a 8.4 in sidewall. That is the nominal size worked out from the code. Makers publish 34.8–35.1 in for real 285/75R18 tires (5 makers).

Diameter34.8 in885 mm
Width11.2 in285 mm
Sidewall8.4 in214 mm
Revs per mile579nominal, published 593–601
Wheel width7.5–9.5 inapproved by every listing

Compare 285/75R18 with other sizes

Set up for: comparing 285/75R18 with a size you're considering · Different situation?

1

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.

2

Size you're considering

 

 

Real 285/75R18 tires: published diameters

Figures from the makers' own data books. They differ from the 34.8 in calculated figure because each tread design and construction measures slightly differently.

Maker (data book)Published diameterRevs per mileApproved wheel widthListings
Falken35–35.1 in595–5987.5–9.5 in2
Goodyear35.1 in5937.5–9.5 in1
Hankook34.8 in600–6017.5–9.5 in2
Nitto34.84–35.08 in—7.5–9.5 in2
Toyo34.8 in5967.5–9.5 in1

Sources: maker data books (PDF), checked 2026-11-05. Brand names identify the data source only.

Equivalent sizes on other wheels

Sizes that appear in the maker data books with a diameter within 3% of 285/75R18. Same diameter is only one part of fitting a different size.

WheelReal sizes within 3% (closest first)
15-inch35x12.50R15 (35.0 in, +0.5%), 35x13.50R15 (35.0 in, +0.5%), 35x14.50R15 (35.0 in, +0.5%)
16-inch35x11.50R16 (35.0 in, +0.5%), 315/75R16 (34.6 in, −0.7%)
17-inch35x11.50R17 (35.0 in, +0.5%), 35x12.50R17 (35.0 in, +0.5%), 315/70R17 (34.4 in, −1.3%)
18-inch305/70R18 (34.8 in, −0.1%), 35x11.50R18 (35.0 in, +0.5%), 35x12.50R18 (35.0 in, +0.5%)
20-inch315/60R20 (34.9 in, +0.1%), 35x11.50R20 (35.0 in, +0.5%), 35x12.50R20 (35.0 in, +0.5%)
22-inch325/50R22 (34.8 in, −0.1%), 295/55R22 (34.8 in, −0.2%), 35x12.50R22 (35.0 in, +0.5%)

Popular comparisons with 285/75R18

285/75R18 vs 35x12.50R18+0.5% diameter

FAQ

How tall is a 285/75R18 tire?

34.8 inches (885 mm) calculated from the size code. Makers publish 34.8–35.1 in for real tires in this size; the difference comes from tread design and construction.

How do you work out the 285/75R18 diameter?

Sidewall = 285 mm × 75% = 213.7 mm. Diameter = 18 in wheel + 2 × 213.7 mm ÷ 25.4 = 34.83 in.

Is 285/75R18 a 35-inch tire?

It is about 34.8 in tall nominally, so it is close to 35 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 285/75R18?

Real sizes within 3% of its diameter include 35x11.50R16 (+0.5%), 35x11.50R17 (+0.5%) and 315/60R20 (+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 285/75R18 make?

About 579 calculated from its unloaded diameter. Makers publish 593–601 revs per mile, measured under load (a loaded tire rolls on a slightly smaller radius), which is why published figures are higher.

Open 285/75R18 in the converter · Tire size chart · 35-inch tires

Important: These are calculated (nominal) dimensions, not a fitment recommendation. Real tires of the same size differ by brand and model (makers allow about ±3% of section height), and width changes with the rim it is mounted on. The math can't see wheel width and offset, clearance at full steering lock and suspension travel, load index, speed rating, or what your vehicle maker approves. Before changing size, check your door-jamb placard and owner's manual and ask a tire professional. A replacement tire must meet or exceed the load index and speed rating on the placard.