The first number 215 is the tire width in millimeters. The 2nd number 60 is used to calculate the sidewall height or "aspect ratio", by percentage. So, the sidewall height of a 215/60 R 16 tire is 60% of 215 = 192. The 3rd number 16 (generally preceded by an "R") is Rim Diameter in inches. This is the diameter of the rims bead seat base, not 245/45-R20 tires are 1.05 inches (26.7 mm) larger in diameter than 225/60-R17 tires and the speedometer difference is 3.7% 245/45-17 225/50-17 Difference; Diameter inches (mm) 25.68 (652.3) 25.86 (656.8) 0.18 (4.5) 0.7%: Width inches (mm) 9.65 (245) 8.86 (225)-0.79 (-20) -8.2%: Circum. inches (mm) 80.68 (2049.26) 81.24 (2063.4) 0.56 (14.14) 0.7%: Sidewall Height inches (mm) 4.34 (110.25) 4.43 (112.5) 0.09 (2.25) 2%: Revolutions per mile (km) 785.33 (487.98) 779.95 Tire Size Calculator - Tire & Wheel Plus Sizing. BETA. 3.76% too fast. 3.76% too fast. 245-50R17, 245-45R17 tire size comparison with 1010tires.com Tire Size calculator. Use our tire calculator to compare tire sizes based on tire diameter, radius, sidewall height, circumference, revs per mile and speedometer difference. The calculation results are presented in the form of visual infographics, on which tire with size 235/45 R17 is on top, and tire with size 235/50 R17 below. Both in the table and in the graph, the tires are compared according to the following indicators: overall diameter, section width, circumference, sidewall height and clearance. Compare 225/65 R17 vs 245/65 R17. Tire Size and Comparison Calculator calculate tire diameter from code and compare speedometer differences for tire sizes. The first number 225 is the tire width in millimeters. The 2nd number 65 is used to calculate the sidewall height or "aspect ratio", by percentage. Compare 225/50 R17 vs 225/65 R17. Tire Size and Comparison Calculator calculate tire diameter from code and compare speedometer differences for tire sizes. The first number 225 is the tire width in millimeters. The 2nd number 50 is used to calculate the sidewall height or "aspect ratio", by percentage. Apr 26, 2022 · You can upsize to the 225/50 R17 which has a difference percentage of just 0.8%. These tyres fit best on rims with a width of 6-8 inches. 245/45 R17 95W, 240/45 The 235/65r17 tire is 0.51 inches (13 mm) taller than the 225/65r17 tire. The diameter of a 235/65r17 tire is 29.03 inches (737.3 mm), while the diameter of a 225/65r17 tire is 28.52 inches (724.3 mm). This slight increase in overall diameter results in the 235-width tire being 1.8% taller. 245/65-R17 tires are 1.54 inches (39 mm) larger in diameter than 215/65-R17 tires and the speedometer difference is 5.2%. ldQv0CA.