235/30R21 tire size in inches
A 235/30R21 tire measures
26.6" tall × 9.3" wide
2.78" sidewall on a 21" wheel. 760 revolutions per mile.
235/30R21 means a tire 235 mm wide, with sidewalls 30% as tall as the tire is wide (71 mm), radial construction (R), for a 21 inch wheel.
235/30R21 specs
| Overall diameter (height) | 26.55 inches (674 mm) |
|---|---|
| Section width | 9.25 inches (235 mm) |
| Sidewall height | 2.78 inches (71 mm) |
| Wheel (rim) diameter | 21 inches |
| Circumference | 83.4 inches (2,119 mm) |
| Revolutions per mile | 760 |
| Revolutions per kilometer | 472 |
| Approximate rim width | 7.5" to 9.0" |
| In inches (flotation style) | 26.6x9.3R21 |
| Aspect ratio | 30% |
Calculated from the size. Real tires differ by brand, model and tread depth, typically by a few tenths of an inch.
Sizes that can replace 235/30R21 on a 21" wheel
These 21" sizes are within 3% of 235/30R21's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 285/25R21 | 26.61" | 11.22" | +0.2% | 60.1 mph | Compare |
| 275/25R21 | 26.41" | 10.83" | −0.5% | 59.7 mph | Compare |
| 225/30R21 | 26.31" | 8.86" | −0.9% | 59.5 mph | Compare |
| 245/30R21 | 26.79" | 9.65" | +0.9% | 60.5 mph | Compare |
| 295/25R21 | 26.81" | 11.61" | +1.0% | 60.6 mph | Compare |
| 265/25R21 | 26.22" | 10.43" | −1.3% | 59.2 mph | Compare |
| 305/25R21 | 27.00" | 12.01" | +1.7% | 61.0 mph | Compare |
| 255/30R21 | 27.02" | 10.04" | +1.8% | 61.1 mph | Compare |
| 255/25R21 | 26.02" | 10.04" | −2.0% | 58.8 mph | Compare |
| 225/35R21 | 27.20" | 8.86" | +2.4% | 61.5 mph | Compare |
| 315/25R21 | 27.20" | 12.40" | +2.4% | 61.5 mph | Compare |
| 265/30R21 | 27.26" | 10.43" | +2.7% | 61.6 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 215/80R13 | 13" | 26.54" | 0.0% | Compare |
| 245/65R14 | 14" | 26.54" | 0.0% | Compare |
| 245/60R15 | 15" | 26.57" | +0.1% | Compare |
| 275/35R19 | 19" | 26.58" | +0.1% | Compare |
| 265/60R14 | 14" | 26.52" | −0.1% | Compare |
| 195/75R15 | 15" | 26.52" | −0.1% | Compare |
| 225/65R15 | 15" | 26.52" | −0.1% | Compare |
| 335/25R20 | 20" | 26.59" | +0.2% | Compare |
| 245/70R13 | 13" | 26.50" | −0.2% | Compare |
| 275/30R20 | 20" | 26.50" | −0.2% | Compare |
| 305/40R17 | 17" | 26.61" | +0.2% | Compare |
| 205/65R16 | 16" | 26.49" | −0.2% | Compare |
One size up or down
- 225/30R21narrower: 26.3" × 8.9"
- 245/30R21wider: 26.8" × 9.6"
- 235/25R21lower profile: 25.6" × 9.3"
- 235/35R21taller sidewall: 27.5" × 9.3"
Compare 235/30R21 with another size
Questions
- How tall is a 235/30R21 tire?
- A 235/30R21 tire is 26.6 inches tall (674 mm), calculated from the size. It is 9.3 inches wide with 2.8 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 235/30R21 mean?
- 235/30R21 means a tire 235 mm wide, with sidewalls 30% as tall as the tire is wide (71 mm), radial construction (R), for a 21 inch wheel.
- How many revolutions per mile does a 235/30R21 tire make?
- About 760 revolutions per mile, based on a circumference of 83.4 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 235/30R21 tire?
- Roughly 7.5" to 9.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 285/25R21 instead of 235/30R21?
- 285/25R21 is +0.06 inches (+0.2%) in overall diameter, so at an indicated 60 mph you would be doing 60.1 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.