275/70R18 dimensions
| Measure | Inches | Millimetres |
|---|---|---|
| Overall height | 33.16 in | 842 mm |
| Section width | 10.83 in | 275 mm |
| Sidewall height | 7.58 in | 192.5 mm |
| Wheel diameter | 18 in | 457 mm |
| Circumference | 104.2 in | 2,646 mm |
| Revolutions per mile | 608.3 |
The math
| Step | Math | Result |
|---|---|---|
| Sidewall | 275 × 70% = 192.5 mm ÷ 25.4 | 7.58 in |
| Overall height | 18 + 2 × 7.58 | 33.16 in |
| Width | 275 mm ÷ 25.4 | 10.83 in |
| Circumference | π × 33.16 | 104.2 in |
| Revs per mile | 63,360 ÷ 104.2 | 608.3 |
With a 7.6 in sidewall this is a very tall sidewall, the kind seen on light-truck and off-road sizes, with plenty of cushion and flex. Real tires vary by brand and model, and the loaded radius under the vehicle is a bit smaller than this unloaded figure.
One step either way on a 18 in wheel
Each row changes one thing and shows the height change against 275/70R18, plus what 60 mph on the speedometer would really be if you swapped to that size.
| Change | Size | Height | Height change | 60 mph shows as | Verdict |
|---|---|---|---|---|---|
| Wider | 285/70R18 (compare) | 33.7 in | +1.7% | 61.0 mph | Close match |
| Narrower | 265/70R18 (compare) | 32.6 in | -1.7% | 59.0 mph | Close match |
| Taller sidewall | 275/75R18 (compare) | 34.2 in | +3.3% | 62.0 mph | Check clearance |
| Shorter sidewall | 275/65R18 (compare) | 32.1 in | -3.3% | 58.0 mph | Check clearance |
| Wider, shorter sidewall | 285/65R18 (compare) | 32.6 in | -1.7% | 59.0 mph | Close match |
| Narrower, taller sidewall | 265/75R18 (compare) | 33.6 in | +1.5% | 60.9 mph | Close match |
Calculated sizes within ±3% on other wheels
Plus and minus sizes that keep the overall height within about 3% (a rule of thumb from Discount Tire and 1010tires), widths within 30 mm. Calculated, not a list of tires on sale: check that a tire exists in that size.
17 in wheels (one wheel size smaller)
| Size | Height | Height change | Width change |
|---|---|---|---|
| 275/75R17 (compare) | 33.2 in | +0.2% | +0 mm |
| 255/80R17 (compare) | 33.1 in | -0.3% | -20 mm |
| 295/70R17 (compare) | 33.3 in | +0.3% | +20 mm |
| 245/85R17 (compare) | 33.4 in | +0.7% | -30 mm |
19 in wheels (one wheel size larger)
| Size | Height | Height change | Width change |
|---|---|---|---|
| 275/65R19 (compare) | 33.1 in | -0.2% | +0 mm |
| 255/70R19 (compare) | 33.1 in | -0.3% | -20 mm |
| 295/60R19 (compare) | 32.9 in | -0.7% | +20 mm |
| 305/60R19 (compare) | 33.4 in | +0.8% | +30 mm |
20 in wheels (two wheel sizes larger)
| Size | Height | Height change | Width change |
|---|---|---|---|
| 305/55R20 (compare) | 33.2 in | +0.2% | +30 mm |
| 255/65R20 (compare) | 33.1 in | -0.3% | -20 mm |
| 275/60R20 (compare) | 33.0 in | -0.5% | +0 mm |
| 285/60R20 (compare) | 33.5 in | +0.9% | +10 mm |
Try it with your numbers
Compare 275/70R18 with another size · Convert to metric or find a 33 in size · Sizes that fit my wheel
Calculated from the size alone. Real tires vary a little by brand and model, and the loaded radius is a bit smaller. Confirm the wheel width range, clearance, load index and speed rating for your vehicle. See how to read a tire size, the load index chart and the speed rating chart.
Browse: all sizes in inches · 275/65R18 · 285/50R18.