Why people go down a wheel size for winter
A smaller wheel with a taller sidewall is a common choice for a second set of winter wheels. It keeps the speedometer and gearing close to stock when the height matches. Whether it suits your vehicle depends on brake clearance (the smaller wheel must clear the calipers), load index and available sizes: this page only does the height math.
Calculated examples (within ±2% height, widths within 20 mm)
225/45R17 (25.0 in) on 16 inch wheels
| Size | Height | Change | Width change | Sidewall |
|---|---|---|---|---|
| 205/55R16 | 24.88 in | -0.38% | -20 mm | 4.44 in |
| 225/50R16 | 24.86 in | -0.46% | +0 mm | 4.43 in |
| 235/50R16 | 25.25 in | +1.12% | +10 mm | 4.63 in |
| 245/45R16 | 24.68 in | -1.17% | +20 mm | 4.34 in |
| 215/55R16 | 25.31 in | +1.36% | -10 mm | 4.66 in |
235/55R19 (29.2 in) on 18 inch wheels
| Size | Height | Change | Width change | Sidewall |
|---|---|---|---|---|
| 235/60R18 | 29.10 in | -0.26% | +0 mm | 5.55 in |
| 255/55R18 | 29.04 in | -0.46% | +20 mm | 5.52 in |
| 215/65R18 | 29.00 in | -0.59% | -20 mm | 5.50 in |
| 225/65R18 | 29.52 in | +1.16% | -10 mm | 5.76 in |
| 245/60R18 | 29.57 in | +1.36% | +10 mm | 5.79 in |
255/45R20 (29.0 in) on 19 inch wheels
| Size | Height | Change | Width change | Sidewall |
|---|---|---|---|---|
| 255/50R19 | 29.04 in | +0.01% | +0 mm | 5.02 in |
| 235/55R19 | 29.18 in | +0.49% | -20 mm | 5.09 in |
| 275/45R19 | 28.74 in | -1.00% | +20 mm | 4.87 in |
| 245/50R19 | 28.65 in | -1.34% | -10 mm | 4.82 in |
| 265/50R19 | 29.43 in | +1.37% | +10 mm | 5.22 in |
Height guideline: about 3% is the usual rule of thumb (Discount Tire’s tire size calculator, 1010tires); tighter keeps the speedometer closer. The sizes are calculated: not a list of tires on sale.
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.