325/40R20 tire size in inches
A 325/40R20 tire measures
30.2" tall × 12.8" wide
5.12" sidewall on a 20" wheel. 667 revolutions per mile.
325/40R20 means a tire 325 mm wide, with sidewalls 40% as tall as the tire is wide (130 mm), radial construction (R), for a 20 inch wheel.
325/40R20 specs
| Overall diameter (height) | 30.24 inches (768 mm) |
|---|---|
| Section width | 12.80 inches (325 mm) |
| Sidewall height | 5.12 inches (130 mm) |
| Wheel (rim) diameter | 20 inches |
| Circumference | 95.0 inches (2,413 mm) |
| Revolutions per mile | 667 |
| Revolutions per kilometer | 414 |
| Approximate rim width | 10.5" to 12.0" |
| In inches (flotation style) | 30.2x12.8R20 |
| Aspect ratio | 40% |
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 325/40R20 on a 20" wheel
These 20" sizes are within 3% of 325/40R20's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 235/55R20 | 30.18" | 9.25" | −0.2% | 59.9 mph | Compare |
| 215/60R20 | 30.16" | 8.46" | −0.3% | 59.8 mph | Compare |
| 285/45R20 | 30.10" | 11.22" | −0.5% | 59.7 mph | Compare |
| 265/50R20 | 30.43" | 10.43" | +0.7% | 60.4 mph | Compare |
| 255/50R20 | 30.04" | 10.04" | −0.7% | 59.6 mph | Compare |
| 295/45R20 | 30.45" | 11.61" | +0.7% | 60.4 mph | Compare |
| 335/40R20 | 30.55" | 13.19" | +1.0% | 60.6 mph | Compare |
| 315/40R20 | 29.92" | 12.40" | −1.0% | 59.4 mph | Compare |
| 245/55R20 | 30.61" | 9.65" | +1.2% | 60.7 mph | Compare |
| 225/60R20 | 30.63" | 8.86" | +1.3% | 60.8 mph | Compare |
| 355/35R20 | 29.78" | 13.98" | −1.5% | 59.1 mph | Compare |
| 225/55R20 | 29.74" | 8.86" | −1.6% | 59.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 335/35R21 | 21" | 30.23" | 0.0% | Compare |
| 235/50R21 | 21" | 30.25" | +0.1% | Compare |
| 285/50R19 | 19" | 30.22" | −0.1% | Compare |
| 265/30R24 | 24" | 30.26" | +0.1% | Compare |
| 305/55R17 | 17" | 30.21" | −0.1% | Compare |
| 315/25R24 | 24" | 30.20" | −0.1% | Compare |
| 225/75R17 | 17" | 30.29" | +0.2% | Compare |
| 295/40R21 | 21" | 30.29" | +0.2% | Compare |
| 355/40R19 | 19" | 30.18" | −0.2% | Compare |
| 225/80R16 | 16" | 30.17" | −0.2% | Compare |
| 315/45R19 | 19" | 30.16" | −0.2% | Compare |
| 275/70R15 | 15" | 30.16" | −0.3% | Compare |
One size up or down
- 315/40R20narrower: 29.9" × 12.4"
- 335/40R20wider: 30.6" × 13.2"
- 325/35R20lower profile: 29.0" × 12.8"
- 325/45R20taller sidewall: 31.5" × 12.8"
Compare 325/40R20 with another size
Questions
- How tall is a 325/40R20 tire?
- A 325/40R20 tire is 30.2 inches tall (768 mm), calculated from the size. It is 12.8 inches wide with 5.1 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 325/40R20 mean?
- 325/40R20 means a tire 325 mm wide, with sidewalls 40% as tall as the tire is wide (130 mm), radial construction (R), for a 20 inch wheel.
- How many revolutions per mile does a 325/40R20 tire make?
- About 667 revolutions per mile, based on a circumference of 95.0 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 325/40R20 tire?
- Roughly 10.5" to 12.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 235/55R20 instead of 325/40R20?
- 235/55R20 is −0.06 inches (−0.2%) in overall diameter, so at an indicated 60 mph you would be doing 59.9 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.