GarageCalc What 265/55R19 means
265 is the section width in millimeters (10.4 in). 55 is the aspect ratio: the sidewall is 55 percent of the width, so 265 × 0.55 = 146 mm (5.7 in). R is radial construction, and 19 is the wheel diameter in inches (483 mm). Stack two sidewalls on the wheel and you get the overall diameter: 483 + 2 × 146 = 774 mm, or 30.5 in.
A full marking adds a load index and speed rating after the size, for example 265/55R19 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 265/55R19
Going up one wheel size, the closest match is 265/50R20 at -0.1% diameter with a 133 mm sidewall instead of 146 mm. Going down one size, 265/60R18 is +0.1% with a taller 159 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 265/55R19 tire?
30.5 inches (774 mm) in overall diameter: the 19-inch wheel (483 mm) plus two 146 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 265/55R19 in inches?
30.5 x 10.4 R19: 30.5 inches tall, 10.4 inches wide, on a 19-inch wheel. The sidewall is 5.7 inches and the circumference is 95.7 inches, so the tire turns 662 times per mile.
What tire sizes are equivalent to 265/55R19?
Within 3 percent of the same diameter on the same 19-inch wheel: 255/55R19 (-1.4%), 275/55R19 (+1.4%), 275/50R19 (-2.1%); on a 20-inch wheel: 265/50R20 (-0.1%), 275/50R20 (+1.1%); on an 18-inch wheel: 265/60R18 (+0.1%), 245/65R18 (+0.2%). The percentage is the diameter change, which is also your speedometer error.
Can I use 275/55R19 instead of 265/55R19?
Dimensionally yes: 275/55R19 is 1.4% taller (+11 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 59.2 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 275 mm.