GarageCalc What 235/40R19 means
235 is the section width in millimeters (9.3 in). 40 is the aspect ratio: the sidewall is 40 percent of the width, so 235 × 0.40 = 94 mm (3.7 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 × 94 = 671 mm, or 26.4 in.
A full marking adds a load index and speed rating after the size, for example 235/40R19 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 235/40R19
Going up one wheel size, the closest match is 235/35R20 at +0.3% diameter with a 82 mm sidewall instead of 94 mm. Going down one size, 215/50R18 is +0.2% with a taller 108 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 235/40R19
Typical factory fitments include Tesla Model 3 (19-inch), Honda Accord Sport (2018 on) and Toyota Camry XSE 19-inch. Tire size changes with trim and wheel option, so confirm on the door-jamb placard before buying.
Frequently asked questions
How tall is a 235/40R19 tire?
26.4 inches (671 mm) in overall diameter: the 19-inch wheel (483 mm) plus two 94 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 235/40R19 in inches?
26.4 x 9.3 R19: 26.4 inches tall, 9.3 inches wide, on a 19-inch wheel. The sidewall is 3.7 inches and the circumference is 82.9 inches, so the tire turns 764 times per mile.
What tire sizes are equivalent to 235/40R19?
Within 3 percent of the same diameter on the same 19-inch wheel: 225/40R19 (-1.2%), 245/40R19 (+1.2%), 255/35R19 (-1.4%); on a 20-inch wheel: 235/35R20 (+0.3%), 225/35R20 (-0.8%); on an 18-inch wheel: 215/50R18 (+0.2%), 235/45R18 (-0.3%). The percentage is the diameter change, which is also your speedometer error.
Can I use 245/40R19 instead of 235/40R19?
Dimensionally yes: 245/40R19 is 1.2% taller (+8 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 59.3 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 245 mm.