245/75R17 — the same height as a 285/60R18, 1.57 in narrower

A tall, narrow light-truck size on a 17-inch wheel — the modern successor to 245/75R16.

Metric notation · Light truck (LT-metric)

Overall diameter: 31.47 in; 799 mm
Section width: 9.65 in; 245 mm
Sidewall height: 7.23 in; 184 mm
Aspect ratio: 75%; sidewall as a share of width
Wheel diameter: 17 in; the hole in the middle
Circumference: 98.9 in; 2511 mm
Revolutions per mile: 640.9; geometric, not measured
Revolutions per km: 398.2; geometric, not measured
Typical load index: 108–129; 2205–4079 lb per tire

LT-metric tires use a stiffer casing at a much higher reference inflation — Load Range C, D or E, meaning 50, 65 or 80 psi. The index band reflects the pressure the casing is rated to hold, not a larger tire.

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

32x11.50R1732.00 in tall+0.53 in
33x10.50R1733.00 in tall+1.53 in
33x12.50R1733.00 in tall+1.53 in

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

Platforms recorded with this size

Half-ton and three-quarter-ton pickups in work specification, and the base fitment on several mid-size trucks aimed at load carrying rather than appearance. The 75-series aspect ratio on a 17-inch wheel is what replaced 245/75R16 as 16-inch truck wheels disappeared.

A hundredth of an inch, and 1.57 in of tread

285/60R18 measures 31.46 in. This size measures 31.47 in — 0.01% apart.

Their section widths are 11.22 in and 9.65 in. Their sidewalls are 6.73 in and 7.23 in. One is a wide, comparatively short-sidewall tire on an 18-inch wheel; the other is a narrow, deep-sidewall tire on a 17. They stand the same height and roll the same distance, and no instrument on the vehicle could tell them apart.

The choice between them is entirely about footprint shape, wheel cost and how much casing sits between the rim and the road — none of which appears in a diameter comparison.

Where height stops being the deciding number

245/70R17 is 0.96 in shorter at 30.50 in; 255/70R17 is 0.41 in shorter at 31.06 in; 265/70R17 is 0.14 in taller at 31.61 in. The 17-inch light-truck range is dense here, and the differences are small enough that width and load rating decide, not height.

Where it sits in the 245 mm range

245/75R16 measures 30.47 in — exactly one inch shorter, because the two sizes differ only in wheel diameter. That is the cleanest possible demonstration of the rule: change nothing but the wheel and the diameter moves by exactly the amount the wheel moved.

245/60R20 measures 31.57 in, which is 0.11 in above this size on a wheel three inches larger and a sidewall of 5.79 in instead of 7.23 in.

Construction

This size is stocked predominantly in LT constructions, at load ranges appropriate to working trucks, and the reference inflation those are rated at is much higher than a passenger casing's. Load range letters — C, D, E and above — are the modern replacement for the old ply-rating system, and they describe the pressure the casing is built to hold rather than a count of anything. A tire marked load range E in this size is not eight or ten plies thick; the number the letter replaced stopped being literal decades ago. The load range and ply rating reference sets out how the two systems map onto each other.

Class: Light truck (LT-metric). Every figure above is computed from the size code, not stored — see how these numbers are calculated.