375/45R20 tire size
375/45R20 is a metric size: 33.3" tall, 14.8" wide, on a 20" rim — about a 33.5x15.00R20. The sidewall is 6.6" and the tire turns 606 times per mile.
375/45R20 specs
| Overall diameter (height) | 33.29" · 845 mm |
|---|---|
| Section width | 14.76" · 375 mm |
| Sidewall height | 6.64" · 169 mm (45% of width) |
| Rim diameter | 20" |
| Circumference | 104.58" · 2.656 m |
| Revolutions per mile | 606 (376 per km) |
| Inch (flotation) equivalent | 33.5x15.00R20 |
Equivalent sizes on a 20" rim
Sizes within ±5% of the overall diameter. Green rows are inside the usual ±3% limit for keeping the speedometer, ABS and gearing right; red rows are bigger changes that need clearance checks.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 275/55R20 common | 31.91" | -4.14% | -100 mm | 57.5 mph | calculate → |
| 275/60R20 common | 32.99" | -0.89% | -100 mm | 59.5 mph | calculate → |
| 275/65R20 common | 34.07" | +2.37% | -100 mm | 61.4 mph | calculate → |
| 265/60R20 common | 32.52" | -2.31% | -110 mm | 58.6 mph | calculate → |
| 305/55R20 common | 33.21" | -0.24% | -70 mm | 59.9 mph | calculate → |
| 285/55R20 common | 32.34" | -2.84% | -90 mm | 58.3 mph | calculate → |
| 285/60R20 common | 33.46" | +0.53% | -90 mm | 60.3 mph | calculate → |
| 33x12.50R20 common | 33.00" | -0.86% | -57 mm | 59.5 mph | calculate → |
| 295/60R20 | 33.94" | +1.95% | -80 mm | 61.2 mph | calculate → |
| 295/55R20 | 32.78" | -1.54% | -80 mm | 59.1 mph | calculate → |
| 285/65R20 | 34.59" | +3.90% | -90 mm | 62.3 mph | calculate → |
| 305/50R20 | 32.01" | -3.84% | -70 mm | 57.7 mph | calculate → |
| 255/60R20 | 32.05" | -3.73% | -120 mm | 57.8 mph | calculate → |
| 315/60R20 | 34.88" | +4.79% | -60 mm | 62.9 mph | calculate → |
| 33x13.50R20 | 33.00" | -0.86% | -32 mm | 59.5 mph | calculate → |
| 33x11.50R20 | 33.00" | -0.86% | -83 mm | 59.5 mph | calculate → |
| 33x12.00R20 | 33.00" | -0.86% | -70 mm | 59.5 mph | calculate → |
| 33x22.00R20 | 33.00" | -0.86% | +184 mm | 59.5 mph | calculate → |
| 325/50R20 | 32.80" | -1.48% | -50 mm | 59.1 mph | calculate → |
| 34x11.50R20 | 34.00" | +2.14% | -83 mm | 61.3 mph | calculate → |
| 305/60R20 | 34.41" | +3.37% | -70 mm | 62.0 mph | calculate → |
| 33x14.50R20 | 33.00" | -0.86% | -7 mm | 59.5 mph | calculate → |
| 355/50R20 | 33.98" | +2.07% | -20 mm | 61.2 mph | calculate → |
| 315/50R20 | 32.40" | -2.66% | -60 mm | 58.4 mph | calculate → |
Try another size against 375/45R20
Questions
What size is 375/45R20 in inches?
375/45R20 is about 33.3" tall and 14.8" wide on a 20-inch rim — roughly a 33.5x15.00R20 in inch sizing.
What does 375/45R20 mean?
375 mm section width, sidewall 45% of the width (6.64"), radial construction, 20-inch rim.
What tire sizes are equivalent to 375/45R20?
On the same 20" rim, within 3% of the diameter: 305/55R20 (-0.24%), 285/60R20 (+0.53%), 33x11.50R20 (-0.86%), 33x12.50R20 (-0.86%), 33x12.00R20 (-0.86%), 33x13.50R20 (-0.86%).
How many revolutions per mile does a 375/45R20 tire make?
About 606 revolutions per mile (circumference 104.6").
How these numbers are computed
Diameter = rim + 2 × sidewall, sidewall = width × aspect ÷ 100, circumference = π × diameter, revolutions per mile = 63,360 ÷ circumference. Real tires differ by brand by a few tenths of an inch. Last reviewed October 14, 2026.