Metric tire size
235/55R20 tire size
A 235/55R20 tire is 30.2 inches (766 mm) tall and 9.3 in wide, for a 20-inch wheel, with a 5.1 in sidewall. That is the nominal size worked out from the code. Makers publish 29.9–30.2 in for real 235/55R20 tires (7 makers).
Compare 235/55R20 with other sizes
Set up for: comparing 235/55R20 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 235/55R20 tires: published diameters
Figures from the makers' own data books. They differ from the 30.2 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 | 30.1 in | 690 | 6.5–8.5 in | 1 |
| Falken | 30.2 in | 697 | 6.5–8.5 in | 1 |
| Goodyear | 30.2 in | 692–693 | 6.5–8.5 in | 2 |
| Hankook | 29.9–30.1 in | 691–695 | 6.5–8.5 in | 4 |
| Nitto | 30.16 in | — | 6.5–8.5 in | 1 |
| Toyo | 30.2 in | 689 | 6.5–8.5 in | 1 |
| Uniroyal | 30.1 in | 690 | 6.5–8.5 in | 1 |
Equivalent sizes on other wheels
Sizes that appear in the maker data books with a diameter within 3% of 235/55R20. Same diameter is only one part of fitting a different size.
| Wheel | Real sizes within 3% (closest first) |
|---|---|
| 15-inch | 30x9.50R15 , 265/75R15 , 265/70R15 |
| 16-inch | 255/70R16 , 215/85R16 , 245/75R16 |
| 17-inch | 225/75R17 , 255/65R17 , 275/60R17 |
| 18-inch | 255/60R18 , 235/65R18 , 265/60R18 |
| 20-inch | 285/45R20 , 255/50R20 , 265/50R20 |
| 22-inch | 295/35R22 , 255/40R22 , 265/40R22 |
Popular comparisons with 235/55R20
FAQ
How tall is a 235/55R20 tire?
30.2 inches (766 mm) calculated from the size code. Makers publish 29.9–30.2 in for real tires in this size; the difference comes from tread design and construction.
How do you work out the 235/55R20 diameter?
Sidewall = 235 mm × 55% = 129.2 mm. Diameter = 20 in wheel + 2 × 129.2 mm ÷ 25.4 = 30.18 in.
Is 235/55R20 a 30-inch tire?
It is about 30.2 in tall nominally, so it is close to 30 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 235/55R20?
Real sizes within 3% of its diameter include 255/70R16 (−0.4%), 225/75R17 (+0.4%) and 255/60R18 (−0.4%). 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 235/55R20 make?
About 668 calculated from its unloaded diameter. Makers publish 689–697 revs per mile, measured under load (a loaded tire rolls on a slightly smaller radius), which is why published figures are higher.
Open 235/55R20 in the converter · Tire size chart · 30-inch tires