245/30R21 tire size in inches
A 245/30R21 tire measures
26.8" tall × 9.6" wide
2.89" sidewall on a 21" wheel. 753 revolutions per mile.
245/30R21 means a tire 245 mm wide, with sidewalls 30% as tall as the tire is wide (74 mm), radial construction (R), for a 21 inch wheel.
245/30R21 specs
| Overall diameter (height) | 26.79 inches (680 mm) |
|---|---|
| Section width | 9.65 inches (245 mm) |
| Sidewall height | 2.89 inches (74 mm) |
| Wheel (rim) diameter | 21 inches |
| Circumference | 84.2 inches (2,138 mm) |
| Revolutions per mile | 753 |
| Revolutions per kilometer | 468 |
| Approximate rim width | 8.0" to 9.5" |
| In inches (flotation style) | 26.8x9.6R21 |
| 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 245/30R21 on a 21" wheel
These 21" sizes are within 3% of 245/30R21's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 295/25R21 | 26.81" | 11.61" | +0.1% | 60.0 mph | Compare |
| 285/25R21 | 26.61" | 11.22" | −0.7% | 59.6 mph | Compare |
| 305/25R21 | 27.00" | 12.01" | +0.8% | 60.5 mph | Compare |
| 235/30R21 | 26.55" | 9.25" | −0.9% | 59.5 mph | Compare |
| 255/30R21 | 27.02" | 10.04" | +0.9% | 60.5 mph | Compare |
| 275/25R21 | 26.41" | 10.83" | −1.4% | 59.2 mph | Compare |
| 225/35R21 | 27.20" | 8.86" | +1.5% | 60.9 mph | Compare |
| 315/25R21 | 27.20" | 12.40" | +1.5% | 60.9 mph | Compare |
| 225/30R21 | 26.31" | 8.86" | −1.8% | 58.9 mph | Compare |
| 265/30R21 | 27.26" | 10.43" | +1.8% | 61.1 mph | Compare |
| 265/25R21 | 26.22" | 10.43" | −2.1% | 58.7 mph | Compare |
| 325/25R21 | 27.40" | 12.80" | +2.3% | 61.4 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 345/25R20 | 20" | 26.79" | 0.0% | Compare |
| 215/40R20 | 20" | 26.77" | −0.1% | Compare |
| 245/35R20 | 20" | 26.75" | −0.1% | Compare |
| 245/25R22 | 22" | 26.82" | +0.1% | Compare |
| 195/70R16 | 16" | 26.75" | −0.1% | Compare |
| 275/50R16 | 16" | 26.83" | +0.1% | Compare |
| 225/55R17 | 17" | 26.74" | −0.2% | Compare |
| 275/45R17 | 17" | 26.74" | −0.2% | Compare |
| 285/30R20 | 20" | 26.73" | −0.2% | Compare |
| 215/70R15 | 15" | 26.85" | +0.2% | Compare |
| 205/85R13 | 13" | 26.72" | −0.2% | Compare |
| 285/35R19 | 19" | 26.85" | +0.2% | Compare |
One size up or down
- 235/30R21narrower: 26.6" × 9.3"
- 255/30R21wider: 27.0" × 10.0"
- 245/25R21lower profile: 25.8" × 9.6"
- 245/35R21taller sidewall: 27.8" × 9.6"
Compare 245/30R21 with another size
Questions
- How tall is a 245/30R21 tire?
- A 245/30R21 tire is 26.8 inches tall (680 mm), calculated from the size. It is 9.6 inches wide with 2.9 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 245/30R21 mean?
- 245/30R21 means a tire 245 mm wide, with sidewalls 30% as tall as the tire is wide (74 mm), radial construction (R), for a 21 inch wheel.
- How many revolutions per mile does a 245/30R21 tire make?
- About 753 revolutions per mile, based on a circumference of 84.2 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 245/30R21 tire?
- Roughly 8.0" to 9.5". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 295/25R21 instead of 245/30R21?
- 295/25R21 is +0.02 inches (+0.1%) in overall diameter, so at an indicated 60 mph you would be doing 60.0 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.