355/45R21 tire size in inches
A 355/45R21 tire measures
33.6" tall × 14.0" wide
6.29" sidewall on a 21" wheel. 601 revolutions per mile.
355/45R21 means a tire 355 mm wide, with sidewalls 45% as tall as the tire is wide (160 mm), radial construction (R), for a 21 inch wheel.
355/45R21 specs
| Overall diameter (height) | 33.58 inches (853 mm) |
|---|---|
| Section width | 13.98 inches (355 mm) |
| Sidewall height | 6.29 inches (160 mm) |
| Wheel (rim) diameter | 21 inches |
| Circumference | 105.5 inches (2,679 mm) |
| Revolutions per mile | 601 |
| Revolutions per kilometer | 373 |
| Approximate rim width | 11.5" to 13.0" |
| In inches (flotation style) | 33.6x14.0R21 |
| Aspect ratio | 45% |
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 355/45R21 on a 21" wheel
These 21" sizes are within 3% of 355/45R21's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 315/50R21 | 33.40" | 12.40" | −0.5% | 59.7 mph | Compare |
| 295/55R21 | 33.78" | 11.61" | +0.6% | 60.4 mph | Compare |
| 325/50R21 | 33.80" | 12.80" | +0.6% | 60.4 mph | Compare |
| 285/55R21 | 33.34" | 11.22" | −0.7% | 59.6 mph | Compare |
| 345/45R21 | 33.22" | 13.58" | −1.1% | 59.4 mph | Compare |
| 305/50R21 | 33.01" | 12.01" | −1.7% | 59.0 mph | Compare |
| 335/50R21 | 34.19" | 13.19" | +1.8% | 61.1 mph | Compare |
| 305/55R21 | 34.21" | 12.01" | +1.9% | 61.1 mph | Compare |
| 275/55R21 | 32.91" | 10.83" | −2.0% | 58.8 mph | Compare |
| 335/45R21 | 32.87" | 13.19" | −2.1% | 58.7 mph | Compare |
| 295/50R21 | 32.61" | 11.61" | −2.9% | 58.3 mph | Compare |
| 345/50R21 | 34.58" | 13.58" | +3.0% | 61.8 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 345/50R20 | 20" | 33.58" | 0.0% | Compare |
| 285/65R19 | 19" | 33.59" | 0.0% | Compare |
| 265/65R20 | 20" | 33.56" | 0.0% | Compare |
| 305/40R24 | 24" | 33.61" | +0.1% | Compare |
| 305/65R18 | 18" | 33.61" | +0.1% | Compare |
| 295/50R22 | 22" | 33.61" | +0.1% | Compare |
| 325/45R22 | 22" | 33.52" | −0.2% | Compare |
| 315/55R20 | 20" | 33.64" | +0.2% | Compare |
| 335/55R19 | 19" | 33.51" | −0.2% | Compare |
| 345/35R24 | 24" | 33.51" | −0.2% | Compare |
| 265/75R18 | 18" | 33.65" | +0.2% | Compare |
| 265/55R22 | 22" | 33.48" | −0.3% | Compare |
One size up or down
- 345/45R21narrower: 33.2" × 13.6"
- 355/40R21lower profile: 32.2" × 14.0"
- 355/50R21taller sidewall: 35.0" × 14.0"
Compare 355/45R21 with another size
Questions
- How tall is a 355/45R21 tire?
- A 355/45R21 tire is 33.6 inches tall (853 mm), calculated from the size. It is 14.0 inches wide with 6.3 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 355/45R21 mean?
- 355/45R21 means a tire 355 mm wide, with sidewalls 45% as tall as the tire is wide (160 mm), radial construction (R), for a 21 inch wheel.
- How many revolutions per mile does a 355/45R21 tire make?
- About 601 revolutions per mile, based on a circumference of 105.5 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 355/45R21 tire?
- Roughly 11.5" to 13.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 315/50R21 instead of 355/45R21?
- 315/50R21 is −0.18 inches (−0.5%) in overall diameter, so at an indicated 60 mph you would be doing 59.7 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.