245/75R16 vs 265/70R16 — two routes to the same 30-inch tire
The pairing a winter-tire buyer usually lands on, where the diameter is held and the width is the whole decision.
265/70R16 is 0.14 in taller than 245/75R16 (0.45%) and 0.79 in wider. A speedometer calibrated for 245/75R16 would under-read by 0.45%.
Measured against each other
Overall diameter
30.47 in30.61 in+0.14 in (+0.45%)Section width
9.65 in / 245 mm10.43 in / 265 mm+0.79 in (+8.16%)Sidewall height
7.23 in7.30 in+0.07 inCircumference
95.7 in96.2 in+0.4 inRevolutions per mile
661.9659.0-3.0Ride height at the axle
——+0.07 inSpeedometer reading
——+0.45% under-read
| Dimension | 245/75R16 | 265/70R16 | Change |
|---|---|---|---|
| Overall diameter | 30.47 in | 30.61 in | +0.14 in (+0.45%) |
| Section width | 9.65 in / 245 mm | 10.43 in / 265 mm | +0.79 in (+8.16%) |
| Sidewall height | 7.23 in | 7.30 in | +0.07 in |
| Circumference | 95.7 in | 96.2 in | +0.4 in |
| Revolutions per mile | 661.9 | 659.0 | -3.0 |
| Ride height at the axle | — | — | +0.07 in |
| Speedometer reading | — | — | +0.45% under-read |
Calibrated for 245/75R16, running 265/70R16
- Dial reads 30
- 30.1 mph
- Dial reads 50
- 50.2 mph
- Dial reads 70
- 70.3 mph
- Odometer counts 100
- 100.5 mi covered
Change either size in the comparison tool, or see the full speed table in the speedometer error calculator.
Two sizes, the same wheel, near-identical height, and 20 mm of width between them. This is the shape of comparison somebody makes when they already know what diameter they want.
How each one gets to 30 and a half inches
- 245/75R16: a 9.65 in casing with a tall 7.23 in sidewall
- 265/70R16: a 10.43 in casing with a shorter 7.30 in sidewall
The sidewalls are within seven hundredths of an inch of each other, which is why the diameters land so close. 75% of a narrow casing and 70% of a wide one work out to almost the same absolute height, and that near-coincidence is the reason both sizes exist on the same shelf.
The difference, such as it is
0.14 in of diameter, 0.45%. Three wheel rotations per mile separate them — 661.9 against 659.0 — and the speedometer shift is under half a mile an hour at any legal speed. There is nothing here to allow for in either direction.
Section width differs by 0.79 in — 8.16% — and that is the entire substance of the choice.
Why the narrower one gets bought
Winter fitments and fleet use, mostly. A narrower casing on the same wheel is usually cheaper, and buyers running a dedicated winter set frequently want the tire to be narrower than the summer one without changing anything the vehicle measures. This pair does that within half a per cent.
It is also the lighter tire of the two, and the one more likely to be offered in a straightforward all-season or studdable winter pattern rather than an aggressive one.
The wider one's argument
Availability and appearance. 265/70R16 is a mainstream light-truck size with a much longer list of tread options, and the extra 0.79 in fills a wheel arch more convincingly. Both of those are real reasons and neither is geometric.
A note on rim width
The two casings are 20 mm apart in nominal section, 9.65 in against 10.43 in, and both codes specify a 16-inch wheel diameter. Wheel width is the term neither code contains, and this site records none, so nothing here can say what either casing would do on any particular set of wheels. Only the direction is safe: the wider a casing sits relative to the rim it was specified against, the flatter its crown and the shorter it stands, which can put a measured figure under the 30.61 in the code predicts. At roughly 0.2 in of section per half inch of rim, that is a larger source of variation than the 0.14 in the two size codes differ by.
Where the pair leads
If the diameter is not what you want held, the 16-inch ladder continues upward: 265/70R16 against 265/75R16 adds an inch on the same casing width, and 285/75R16 reaches the 33-inch class without leaving the wheel.