285/35R21 dimensions
| Measure | Inches | Millimetres |
|---|---|---|
| Overall height | 28.85 in | 733 mm |
| Section width | 11.22 in | 285 mm |
| Sidewall height | 3.93 in | 99.8 mm |
| Wheel diameter | 21 in | 533 mm |
| Circumference | 90.6 in | 2,302 mm |
| Revolutions per mile | 699.0 |
The math
| Step | Math | Result |
|---|---|---|
| Sidewall | 285 × 35% = 99.8 mm ÷ 25.4 | 3.93 in |
| Overall height | 21 + 2 × 3.93 | 28.85 in |
| Width | 285 mm ÷ 25.4 | 11.22 in |
| Circumference | π × 28.85 | 90.6 in |
| Revs per mile | 63,360 ÷ 90.6 | 699.0 |
With a 3.9 in sidewall this is a medium sidewall: a balance of cushion and response. 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 21 in wheel
Each row changes one thing and shows the height change against 285/35R21, 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 | 295/35R21 (compare) | 29.1 in | +1.0% | 60.6 mph | Close match |
| Narrower | 275/35R21 (compare) | 28.6 in | -1.0% | 59.4 mph | Close match |
| Taller sidewall | 285/40R21 (compare) | 30.0 in | +3.9% | 62.3 mph | Check clearance |
| Shorter sidewall | 285/30R21 (compare) | 27.7 in | -3.9% | 57.7 mph | Check clearance |
| Wider, shorter sidewall | 295/30R21 (compare) | 28.0 in | -3.1% | 58.2 mph | Check clearance |
| Narrower, taller sidewall | 275/40R21 (compare) | 29.7 in | +2.8% | 61.7 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.
20 in wheels (one wheel size smaller)
| Size | Height | Height change | Width change |
|---|---|---|---|
| 285/40R20 (compare) | 29.0 in | +0.4% | +0 mm |
| 315/35R20 (compare) | 28.7 in | -0.6% | +30 mm |
| 255/45R20 (compare) | 29.0 in | +0.6% | -30 mm |
| 275/40R20 (compare) | 28.7 in | -0.7% | -10 mm |
22 in wheels (one wheel size larger)
| Size | Height | Height change | Width change |
|---|---|---|---|
| 295/30R22 (compare) | 29.0 in | +0.4% | +10 mm |
| 285/30R22 (compare) | 28.7 in | -0.4% | +0 mm |
| 255/35R22 (compare) | 29.0 in | +0.6% | -30 mm |
| 305/30R22 (compare) | 29.2 in | +1.2% | +20 mm |
23 in wheels (two wheel sizes larger)
| Size | Height | Height change | Width change |
|---|---|---|---|
| 295/25R23 (compare) | 28.8 in | -0.2% | +10 mm |
| 305/25R23 (compare) | 29.0 in | +0.5% | +20 mm |
| 255/30R23 (compare) | 29.0 in | +0.6% | -30 mm |
| 285/25R23 (compare) | 28.6 in | -0.8% | +0 mm |
Try it with your numbers
Compare 285/35R21 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 · 275/50R21 · 295/35R21.