Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/30-21 | 325/25-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.02 (686.4) | 27.4 (695.9) | 0.37 (9.5) 1.4% |
| Width inches (mm) | 10.04 (255) | 12.8 (325) | 2.76 (70) 27.5% |
| Circum. inches (mm) | 84.9 (2156.39) | 86.07 (2186.23) | 1.18 (29.85) 1.4% |
| Sidewall Height inches (mm) | 3.01 (76.5) | 3.2 (81.25) | 0.19 (4.75) 6.2% |
| Revolutions per mile (km) | 746.31 (463.74) | 736.13 (457.41) | -10.19 (-6.33) -1.4% |
325/25-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.28 mph (32.63 km/h) |
| 25 mph (40.23 km/h) | 25.35 mph (40.79 km/h) |
| 30 mph (48.28 km/h) | 30.42 mph (48.95 km/h) |
| 35 mph (56.33 km/h) | 35.48 mph (57.11 km/h) |
| 40 mph (64.37 km/h) | 40.55 mph (65.26 km/h) |
| 45 mph (72.42 km/h) | 45.62 mph (73.42 km/h) |
| 50 mph (80.47 km/h) | 50.69 mph (81.58 km/h) |
| 55 mph (88.51 km/h) | 55.76 mph (89.74 km/h) |
| 60 mph (96.56 km/h) | 60.83 mph (97.9 km/h) |
| 65 mph (104.61 km/h) | 65.9 mph (106.06 km/h) |
| 70 mph (112.65 km/h) | 70.97 mph (114.21 km/h) |
| 75 mph (120.7 km/h) | 76.04 mph (122.37 km/h) |
| 80 mph (128.75 km/h) | 81.11 mph (130.53 km/h) |
| 85 mph (136.79 km/h) | 86.18 mph (138.69 km/h) |
| 90 mph (144.84 km/h) | 91.25 mph (146.85 km/h) |
| 95 mph (152.89 km/h) | 96.31 mph (155 km/h) |
| 100 mph (160.93 km/h) | 101.38 mph (163.16 km/h) |
| 2.35 | 2.73 | 2.94 | 3.07 | 3.21 | 3.31 | 3.42 | 3.55 | 3.73 | 3.91 | 4.11 | 4.27 | 4.56 | 4.88 | 5.13 | 5.29 | 5.38 | 5.71 | 6.17 | 7.17 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1873 | 2176 | 2344 | 2447 | 2559 | 2639 | 2726 | 2830 | 2973 | 3117 | 3276 | 3404 | 3635 | 3890 | 4089 | 4217 | 4289 | 4552 | 4918 | 5716 |
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