GarageCalc What 225/50R17 means
225 is the section width in millimeters (8.9 in). 50 is the aspect ratio: the sidewall is 50 percent of the width, so 225 × 0.50 = 113 mm (4.4 in). R is radial construction, and 17 is the wheel diameter in inches (432 mm). Stack two sidewalls on the wheel and you get the overall diameter: 432 + 2 × 113 = 657 mm, or 25.9 in.
A full marking adds a load index and speed rating after the size, for example 225/50R17 91V. Those two codes set how much weight and speed the tire is certified for; look them up in the load index chart and the speed rating chart.
Plus and minus sizing from 225/50R17
Going up one wheel size, the closest match is 225/45R18 at +0.4% diameter with a 101 mm sidewall instead of 113 mm. Going down one size, 225/55R16 is -0.4% with a taller 124 mm sidewall for more comfort and pothole margin. Anything inside 3 percent keeps the speedometer, ABS and gearing effectively stock; the comparison calculator shows the full speedometer table for any pair.
Which cars come with 225/50R17
Typical factory fitments include Honda Accord LX and EX (2018-2022) and Audi A4 (B8). Tire size changes with trim and wheel option, so confirm on the door-jamb placard before buying.
Frequently asked questions
How tall is a 225/50R17 tire?
25.9 inches (657 mm) in overall diameter: the 17-inch wheel (432 mm) plus two 113 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 225/50R17 in inches?
25.9 x 8.9 R17: 25.9 inches tall, 8.9 inches wide, on a 17-inch wheel. The sidewall is 4.4 inches and the circumference is 81.2 inches, so the tire turns 780 times per mile.
What tire sizes are equivalent to 225/50R17?
Within 3 percent of the same diameter on the same 17-inch wheel: 205/55R17 (+0.1%), 245/45R17 (-0.7%), 215/50R17 (-1.5%); on an 18-inch wheel: 225/45R18 (+0.4%), 245/40R18 (-0.5%); on a 16-inch wheel: 225/55R16 (-0.4%), 205/60R16 (-0.7%). The percentage is the diameter change, which is also your speedometer error.
Can I use 235/50R17 instead of 225/50R17?
Dimensionally yes: 235/50R17 is 1.5% taller (+10 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 59.1 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 235 mm.