How tall is a 35 inch tire, really?
Answer
34.83–35.10 in
"35-inch" is a category, not a measurement. Of the sizes in this catalogue that people call 35s, the geometric diameters run from 34.83 in to 35.10 in — a spread of 0.27 in between tires sold under the same name.
The working
- 35x12.50R15
- 35.00 in tall, 12.50 in wide
- 35x12.50R16
- 35.00 in tall, 12.50 in wide
- 35x11.50R17
- 35.00 in tall, 11.50 in wide
- 35x12.50R17
- 35.00 in tall, 12.50 in wide
- 35x12.50R18
- 35.00 in tall, 12.50 in wide
- 35x12.50R20
- 35.00 in tall, 12.50 in wide
- 295/65R20
- 35.10 in tall, 11.61 in wide
- 285/75R18
- 34.83 in tall, 11.22 in wide
Two populations under one label
Ask a flotation size and you get an exact answer: 35x12.50R17, 35x12.50R20, 35x11.50R17 and their siblings are all 35.00 in, because the number is the diameter. Ask a metric size and you get an estimate that is usually generous. The gap between those two habits is where every disagreement about 35s starts.
The best-known metric "35s" are the furthest from 35
- 315/70R17 — 34.36 in. The classic 17-inch answer, and 0.64 in short.
- 285/65R20 — 34.59 in. The 20-inch equivalent, 0.41 in short.
Both are widely listed as 35-inch equivalents and neither reaches 34.6. Put a truck on 315/70R17 instead of a real 35 and the axle ends up around a third of an inch closer to the ground, with a marginally shorter circumference turning underneath it all day.
The metric sizes that do reach it
- 295/65R20 — 35.10 in. Over the mark rather than under.
- 285/75R18 — 34.83 in. The closest of the near-misses.
- 325/60R20 — 35.35 in. Taller than a flotation 35 and much wider than most people expect.
Between 34.36 and 35.35 there is a full inch of range in tires people describe with the same two characters. That is more than twice the looseness carried by the 33-inch label.
One height, several shapes
Every flotation 35 stands 35.00 in and they are not otherwise alike. A 35x12.50R15 carries 10.00 in of sidewall; a 35x12.50R20 carries 7.50 in. Same overall height, two and a half inches of difference in how much of that height is rubber rather than wheel — which is why two tires with the same name behave nothing alike when aired down.
Reading past the nickname
If a fitment claim rests on a "35", it rests on a number that could be almost half an inch either side of 35.00. Working from the code instead removes the ambiguity in one step — the 315/70R17 against a true 35 shows what the 0.64 in looks like, and why the width of the two is far more similar than the height. For the underlying reason the two notations behave differently, see metric versus imperial notation.