GarageCalc What 225/50R16 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 16 is the wheel diameter in inches (406 mm). Stack two sidewalls on the wheel and you get the overall diameter: 406 + 2 × 113 = 631 mm, or 24.9 in.
A full marking adds a load index and speed rating after the size, for example 225/50R16 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 225/50R16
Going up one wheel size, the closest match is 225/45R17 at +0.5% diameter with a 101 mm sidewall instead of 113 mm. Going down one size, 205/60R15 is -0.7% with a taller 123 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.
Frequently asked questions
How tall is a 225/50R16 tire?
24.9 inches (631 mm) in overall diameter: the 16-inch wheel (406 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 225/50R16 in inches?
24.9 x 8.9 R16: 24.9 inches tall, 8.9 inches wide, on a 16-inch wheel. The sidewall is 4.4 inches and the circumference is 78.1 inches, so the tire turns 811 times per mile.
What tire sizes are equivalent to 225/50R16?
Within 3 percent of the same diameter on the same 16-inch wheel: 205/55R16 (+0.1%), 215/55R16 (+1.8%); on a 17-inch wheel: 225/45R17 (+0.5%), 245/40R17 (-0.6%); on a 15-inch wheel: 205/60R15 (-0.7%), 215/60R15 (+1.2%). The percentage is the diameter change, which is also your speedometer error.