GarageCalc What 215/75R16 means
215 is the section width in millimeters (8.5 in). 75 is the aspect ratio: the sidewall is 75 percent of the width, so 215 × 0.75 = 161 mm (6.3 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 × 161 = 729 mm, or 28.7 in.
A full marking adds a load index and speed rating after the size, for example 215/75R16 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 215/75R16
Going up one wheel size, the closest match is 225/65R17 at -0.6% diameter with a 146 mm sidewall instead of 161 mm. Going down one size, 235/75R15 is +0.6% with a taller 176 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 215/75R16 tire?
28.7 inches (729 mm) in overall diameter: the 16-inch wheel (406 mm) plus two 161 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 215/75R16 in inches?
28.7 x 8.5 R16: 28.7 inches tall, 8.5 inches wide, on a 16-inch wheel. The sidewall is 6.3 inches and the circumference is 90.2 inches, so the tire turns 703 times per mile.
What tire sizes are equivalent to 215/75R16?
Within 3 percent of the same diameter on the same 16-inch wheel: 235/70R16 (+0.9%), 225/70R16 (-1.0%), 225/75R16 (+2.1%); on a 17-inch wheel: 225/65R17 (-0.6%), 235/65R17 (+1.2%); on a 15-inch wheel: 235/75R15 (+0.6%), 225/75R15 (-1.4%). The percentage is the diameter change, which is also your speedometer error.
Can I use 225/70R16 instead of 215/75R16?
Dimensionally yes: 225/70R16 is 1.0% shorter (-8 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 60.6 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 225 mm.