Metric tire size
275/40R20 tire size
A 275/40R20 tire is 28.7 inches (728 mm) tall and 10.8 in wide, for a 20-inch wheel, with a 4.3 in sidewall. That is the nominal size worked out from the code. Makers publish 28.4–29 in for real 275/40R20 tires (6 makers).
Compare 275/40R20 with other sizes
Set up for: comparing 275/40R20 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 275/40R20 tires: published diameters
Figures from the makers' own data books. They differ from the 28.7 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 | 28.6 in | 726 | 9–11 in | 1 |
| Falken | 28.7–29 in | 717–725 | 9–11 in | 2 |
| Goodyear | 28.7 in | 729 | 9–11 in | 1 |
| Hankook | 28.4–28.6 in | 727–730 | 9–11 in | 4 |
| Nitto | 28.62–28.78 in | — | 9–11 in | 3 |
| Toyo | 28.7 in | 725 | 9–11 in | 1 |
Equivalent sizes on other wheels
Sizes that appear in the maker data books with a diameter within 3% of 275/40R20. Same diameter is only one part of fitting a different size.
| Wheel | Real sizes within 3% (closest first) |
|---|---|
| 15-inch | 235/75R15 , 225/75R15 , 255/70R15 |
| 16-inch | 225/70R16 , 235/70R16 , 255/65R16 |
| 17-inch | 225/65R17 , 275/55R17 , 235/65R17 |
| 18-inch | 225/60R18 , 245/55R18 , 305/45R18 |
| 20-inch | 245/45R20 , 315/35R20 , 305/35R20 |
| 22-inch | 335/25R22 , 285/30R22 , 275/30R22 |
Popular comparisons with 275/40R20
FAQ
How tall is a 275/40R20 tire?
28.7 inches (728 mm) calculated from the size code. Makers publish 28.4–29 in for real tires in this size; the difference comes from tread design and construction.
How do you work out the 275/40R20 diameter?
Sidewall = 275 mm × 40% = 110.0 mm. Diameter = 20 in wheel + 2 × 110.0 mm ÷ 25.4 = 28.66 in.
Is 275/40R20 a 29-inch tire?
It is about 28.7 in tall nominally, so it is close to 29 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 275/40R20?
Real sizes within 3% of its diameter include 225/70R16 (−0.9%), 225/65R17 (−0.5%) and 225/60R18 (−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 275/40R20 make?
About 704 calculated from its unloaded diameter. Makers publish 717–730 revs per mile, measured under load (a loaded tire rolls on a slightly smaller radius), which is why published figures are higher.
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