Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/30-21 | 325/25-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.2 (716.4) | 27.4 (695.9) | -0.81 (-20.5) -2.9% |
| Width inches (mm) | 12.01 (305) | 12.8 (325) | 0.79 (20) 6.6% |
| Circum. inches (mm) | 88.61 (2250.64) | 86.07 (2186.23) | -2.54 (-64.4) -2.9% |
| Sidewall Height inches (mm) | 3.6 (91.5) | 3.2 (81.25) | -0.4 (-10.25) -11.2% |
| Revolutions per mile (km) | 715.06 (444.32) | 736.13 (457.41) | 21.06 (13.09) 2.9% |
325/25-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.43 mph (31.27 km/h) |
| 25 mph (40.23 km/h) | 24.28 mph (39.08 km/h) |
| 30 mph (48.28 km/h) | 29.14 mph (46.9 km/h) |
| 35 mph (56.33 km/h) | 34 mph (54.72 km/h) |
| 40 mph (64.37 km/h) | 38.86 mph (62.53 km/h) |
| 45 mph (72.42 km/h) | 43.71 mph (70.35 km/h) |
| 50 mph (80.47 km/h) | 48.57 mph (78.16 km/h) |
| 55 mph (88.51 km/h) | 53.43 mph (85.98 km/h) |
| 60 mph (96.56 km/h) | 58.28 mph (93.8 km/h) |
| 65 mph (104.61 km/h) | 63.14 mph (101.61 km/h) |
| 70 mph (112.65 km/h) | 68 mph (109.43 km/h) |
| 75 mph (120.7 km/h) | 72.85 mph (117.25 km/h) |
| 80 mph (128.75 km/h) | 77.71 mph (125.06 km/h) |
| 85 mph (136.79 km/h) | 82.57 mph (132.88 km/h) |
| 90 mph (144.84 km/h) | 87.42 mph (140.7 km/h) |
| 95 mph (152.89 km/h) | 92.28 mph (148.51 km/h) |
| 100 mph (160.93 km/h) | 97.14 mph (156.33 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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