255/55R19 — half an inch of sidewall per inch of wheel
Four wheels from 16 to 19 inches, one section width, one rolling diameter, and an exactly regular trade.
Metric notation · Crossover and SUV
- Overall diameter
- 30.04 in
- 763 mm
- Section width
- 10.04 in
- 255 mm
- Sidewall height
- 5.52 in
- 140 mm
- Aspect ratio
- 55%
- sidewall as a share of width
- Wheel diameter
- 19 in
- the hole in the middle
- Circumference
- 94.4 in
- 2397 mm
- Revolutions per mile
- 671.3
- geometric, not measured
- Revolutions per km
- 417.1
- geometric, not measured
- Typical load index
- 98–116
- 1653–2756 lb per tire
Crossovers are heavier than the cars they share size families with, so the same nominal size is produced at a higher index for SUV fitment than for passenger fitment. Two tires wearing the same size code can carry materially different loads.
The load-index range shown is the band this CLASS of size is typically produced in — not a list of what is in stock for this exact size today. Load index and speed symbol are printed on the sidewall of the specific tire you are holding, and the required minimum is on the placard of the specific vehicle you are fitting. Read both.
Nearest real sizes in imperial notation, same wheel
Compare any two sizes, including ones this site has no page for, in the comparison tool.
Mid-size and full-size crossovers on 19-inch wheels. On this wheel diameter the size sits in a category of its own: every other 19-inch entry in this catalogue below it is a performance fitment under 28 in tall.
The trade, four times over
| Size | Wheel | Sidewall | Diameter |
|---|---|---|---|
| 255/70R16 | 16 in | 7.03 in | 30.06 in |
| 255/65R17 | 17 in | 6.53 in | 30.05 in |
| 255/60R18 | 18 in | 6.02 in | 30.05 in |
| 255/55R19 | 19 in | 5.52 in | 30.04 in |
Read the sidewall column downwards: 7.03, 6.53, 6.02, 5.52. Each step is almost exactly half an inch, and each step buys one inch of wheel diameter — which is to say half an inch at the top of the tire and half an inch at the bottom.
That is why the diameter column barely moves. The whole set spans 0.01 in, which is 0.04% from top to bottom.
At 255 mm, a five-point change in the middle number moves the sidewall by just over half an inch, and that is the only reason the arithmetic comes out this cleanly. On a 195 mm casing the same five points would be worth considerably less, and a stack built the same way would drift.
This size's own position
It carries the least sidewall of the four and sits on the largest wheel: 5.52 in of casing against the 16-inch entry's 7.03 in, in exchange for three inches of rim.
What is nearby but not in the stack
235/65R18 measures 30.03 in — 0.05% from this size, with 0.79 in less section width. 30x9.50R15 measures 30.00 in, a flotation size on a 15-inch wheel landing 0.14% below.
265/50R20 is 0.39 in taller at 30.43 in, and 245/50R20 is 0.40 in shorter at 29.65 in. The 20-inch wheel does not continue this particular stack, because there is no 255/50R20 in general circulation.
Why the stack stops at nineteen
There is no 255/50R20 in general circulation, which is what breaks the pattern above. The reason is demand rather than arithmetic: a vehicle willing to run a 20-inch wheel is usually willing to run a wider tire on it, so the market supplies 265/50R20 instead and the 255 mm column ends here.
Plus-size stacks are built where somebody will buy every rung. Where they are not, the ladder simply stops, which the plus sizing reference covers in general terms.
Class: Crossover and SUV. Every figure above is computed from the size code, not stored — see how these numbers are calculated.