GarageCalc What 185/50R16 means
185 is the section width in millimeters (7.3 in). 50 is the aspect ratio: the sidewall is 50 percent of the width, so 185 × 0.50 = 93 mm (3.6 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 × 93 = 591 mm, or 23.3 in.
A full marking adds a load index and speed rating after the size, for example 185/50R16 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 185/50R16
Going up one wheel size, the closest match is 205/40R17 at +0.7% diameter with a 82 mm sidewall instead of 93 mm. Going down one size, 175/60R15 is -0.1% with a taller 105 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 185/50R16 tire?
23.3 inches (591 mm) in overall diameter: the 16-inch wheel (406 mm) plus two 93 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 185/50R16 in inches?
23.3 x 7.3 R16: 23.3 inches tall, 7.3 inches wide, on a 16-inch wheel. The sidewall is 3.6 inches and the circumference is 73.1 inches, so the tire turns 866 times per mile.
What tire sizes are equivalent to 185/50R16?
Within 3 percent of the same diameter on the same 16-inch wheel: 205/45R16 (-0.1%), 195/45R16 (-1.6%), 195/50R16 (+1.7%); on a 17-inch wheel: 205/40R17 (+0.7%); on a 15-inch wheel: 175/60R15 (-0.1%), 165/65R15 (+0.7%). The percentage is the diameter change, which is also your speedometer error.
Can I use 195/45R16 instead of 185/50R16?
Dimensionally yes: 195/45R16 is 1.6% shorter (-10 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 61.0 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 195 mm.