345/35R21 tire size in inches
A 345/35R21 tire measures
30.5" tall × 13.6" wide
4.75" sidewall on a 21" wheel. 661 revolutions per mile.
345/35R21 means a tire 345 mm wide, with sidewalls 35% as tall as the tire is wide (121 mm), radial construction (R), for a 21 inch wheel.
345/35R21 specs
| Overall diameter (height) | 30.51 inches (775 mm) |
|---|---|
| Section width | 13.58 inches (345 mm) |
| Sidewall height | 4.75 inches (121 mm) |
| Wheel (rim) diameter | 21 inches |
| Circumference | 95.8 inches (2,434 mm) |
| Revolutions per mile | 661 |
| Revolutions per kilometer | 411 |
| Approximate rim width | 11.5" to 13.0" |
| In inches (flotation style) | 30.5x13.6R21 |
| Aspect ratio | 35% |
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 345/35R21 on a 21" wheel
These 21" sizes are within 3% of 345/35R21's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 305/40R21 | 30.61" | 12.01" | +0.3% | 60.2 mph | Compare |
| 265/45R21 | 30.39" | 10.43" | −0.4% | 59.8 mph | Compare |
| 245/50R21 | 30.65" | 9.65" | +0.5% | 60.3 mph | Compare |
| 295/40R21 | 30.29" | 11.61" | −0.7% | 59.6 mph | Compare |
| 225/55R21 | 30.74" | 8.86" | +0.8% | 60.5 mph | Compare |
| 275/45R21 | 30.74" | 10.83" | +0.8% | 60.5 mph | Compare |
| 235/50R21 | 30.25" | 9.25" | −0.8% | 59.5 mph | Compare |
| 335/35R21 | 30.23" | 13.19" | −0.9% | 59.5 mph | Compare |
| 355/35R21 | 30.78" | 13.98" | +0.9% | 60.5 mph | Compare |
| 315/40R21 | 30.92" | 12.40" | +1.4% | 60.8 mph | Compare |
| 255/45R21 | 30.04" | 10.04" | −1.5% | 59.1 mph | Compare |
| 255/50R21 | 31.04" | 10.04" | +1.7% | 61.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 245/70R17 | 17" | 30.50" | 0.0% | Compare |
| 225/65R19 | 19" | 30.52" | 0.0% | Compare |
| 325/45R19 | 19" | 30.52" | 0.0% | Compare |
| 275/30R24 | 24" | 30.50" | 0.0% | Compare |
| 265/60R18 | 18" | 30.52" | 0.0% | Compare |
| 245/65R18 | 18" | 30.54" | +0.1% | Compare |
| 265/55R19 | 19" | 30.48" | −0.1% | Compare |
| 245/75R16 | 16" | 30.47" | −0.1% | Compare |
| 285/60R17 | 17" | 30.46" | −0.1% | Compare |
| 335/40R20 | 20" | 30.55" | +0.1% | Compare |
| 295/45R20 | 20" | 30.45" | −0.2% | Compare |
| 265/65R17 | 17" | 30.56" | +0.2% | Compare |
One size up or down
- 335/35R21narrower: 30.2" × 13.2"
- 355/35R21wider: 30.8" × 14.0"
- 345/30R21lower profile: 29.1" × 13.6"
- 345/40R21taller sidewall: 31.9" × 13.6"
Compare 345/35R21 with another size
Questions
- How tall is a 345/35R21 tire?
- A 345/35R21 tire is 30.5 inches tall (775 mm), calculated from the size. It is 13.6 inches wide with 4.8 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 345/35R21 mean?
- 345/35R21 means a tire 345 mm wide, with sidewalls 35% as tall as the tire is wide (121 mm), radial construction (R), for a 21 inch wheel.
- How many revolutions per mile does a 345/35R21 tire make?
- About 661 revolutions per mile, based on a circumference of 95.8 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 345/35R21 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 305/40R21 instead of 345/35R21?
- 305/40R21 is +0.10 inches (+0.3%) in overall diameter, so at an indicated 60 mph you would be doing 60.2 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.