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Tire sizes

32x11.50R15 — one of only two sizes called a 32

A 32 is a rare thing to be able to buy, and on a 15-inch wheel there is no alternative route to one.

Flotation (imperial) notation · Flotation (imperial)

Overall diameter
32.00 in
813 mm
Section width
11.50 in
292 mm
Sidewall height
8.50 in
216 mm
Aspect ratio
73.9%
sidewall as a share of width
Wheel diameter
15 in
the hole in the middle
Circumference
100.5 in
2553 mm
Revolutions per mile
630.3
geometric, not measured
Revolutions per km
391.6
geometric, not measured
Typical load index
108–128
2205–3968 lb per tire

Flotation sizes are almost always LT construction, so they share the light-truck band. Speed symbols run low because the aggressive tread patterns these sizes are sold in are rated against heat build-up, not against sustained high speed.

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 metric notation, same wheel

  • 235/75R1528.88 in tall-3.12 in
  • 225/75R1528.29 in tall-3.71 in
  • 215/75R1527.70 in tall-4.30 in

Compare any two sizes, including ones this site has no page for, in the comparison tool.

Nothing in the vehicle records here lists 32x11.50R15. It survives as a replacement size for 15-inch wheels on older short-wheelbase off-road vehicles.

Two 32s, and they are the same tire

32x11.50R15 and 32x11.50R17 both compute to 32.00 in on 11.50 in of section, and both turn 630.3 times in a mile. The 15-inch version carries 8.50 in of casing; the 17-inch version carries 7.50 in.

Those two codes are the entire 32-inch flotation offering in this catalogue. Between the 31s and the 33s — a band the industry populates heavily in metric notation — imperial notation has one width on two wheels and nothing else.

The metric 32s are all on bigger wheels

Four metric codes land within 0.07 in of 32.00 in:

  • 255/65R19 — 32.05 in, 10.04 in wide
  • 255/70R18 — 32.06 in, 10.04 in wide
  • 255/75R17 — 32.06 in, 10.04 in wide
  • 275/65R18 — 32.07 in, 10.83 in wide

Every one of them needs at least a 17-inch wheel, and every one is narrower than this size by between 0.67 in and 1.46 in. On a 15-inch wheel there is no metric route to 32 in at all: the tallest 15-inch metric code catalogued here is 235/75R15 at 28.88 in, more than three inches short.

It is also worth noticing which of the five is smallest. The flotation code is the one that says 32 and the one that measures least — 32.00 in against 32.05 to 32.07 in — because it states a round figure while the metric codes land wherever their arithmetic puts them. The whole-inch name is the floor of the group rather than its centre.

What the 15-inch ladder costs to climb

Step Diameter Change Section width
30x9.50R15 30.00 in −2.00 in (6.25%) −2.00 in
31x10.50R15 31.00 in −1.00 in (3.13%) −1.00 in
32x11.50R15 32.00 in 11.50 in
33x12.50R15 33.00 in +1.00 in (3.13%) +1.00 in
35x12.50R15 35.00 in +3.00 in (9.38%) +1.00 in

The bottom row is where the pattern breaks. Every step below it adds an inch of width for an inch of height; the last one adds three inches of height and one of width, because 12.50 in is where the 15-inch range stops widening. That makes this size the last rung at which the two dimensions are still moving together.

Related

Class: Flotation (imperial). Every figure above is computed from the size code, not stored — see how these numbers are calculated.