Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
245/30r21 vs 245/35r21 Tire Comparison Side By Side
  245/30-21 245/35-21 Difference
Diameter inches (mm) 26.79 (680.4) 27.75 (704.9) 0.96 (24.5) 3.6%
Width inches (mm) 9.65 (245) 9.65 (245) 0 (0) 0%
Circum. inches (mm) 84.16 (2137.54) 87.19 (2214.51) 3.03 (76.97) 3.6%
Sidewall Height inches (mm) 2.89 (73.5) 3.38 (85.75) 0.48 (12.25) 16.7%
Revolutions per mile (km) 752.9 (467.83) 726.73 (451.57) -26.17 (-16.26) -3.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.72 mph (33.35 km/h)
25 mph (40.23 km/h)25.9 mph (41.68 km/h)
30 mph (48.28 km/h)31.08 mph (50.02 km/h)
35 mph (56.33 km/h)36.26 mph (58.36 km/h)
40 mph (64.37 km/h)41.44 mph (66.69 km/h)
45 mph (72.42 km/h)46.62 mph (75.03 km/h)
50 mph (80.47 km/h)51.8 mph (83.36 km/h)
55 mph (88.51 km/h)56.98 mph (91.7 km/h)
60 mph (96.56 km/h)62.16 mph (100.04 km/h)
65 mph (104.61 km/h)67.34 mph (108.37 km/h)
70 mph (112.65 km/h)72.52 mph (116.71 km/h)
75 mph (120.7 km/h)77.7 mph (125.05 km/h)
80 mph (128.75 km/h)82.88 mph (133.38 km/h)
85 mph (136.79 km/h)88.06 mph (141.72 km/h)
90 mph (144.84 km/h)93.24 mph (150.06 km/h)
95 mph (152.89 km/h)98.42 mph (158.39 km/h)
100 mph (160.93 km/h)103.6 mph (166.73 km/h)

Gear Ratio / RPMs for New Tire (@ 65 mph)
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
18492148231424162526260526912794293530773234336035893840403741634234449448565643
Better Fuel Economy Factory Ratios Increased Power

Most Popular 245/30-R21 Comparisons

To Top