GarageCalc What 295/35R20 means
295 is the section width in millimeters (11.6 in). 35 is the aspect ratio: the sidewall is 35 percent of the width, so 295 × 0.35 = 103 mm (4.1 in). R is radial construction, and 20 is the wheel diameter in inches (508 mm). Stack two sidewalls on the wheel and you get the overall diameter: 508 + 2 × 103 = 715 mm, or 28.1 in.
A full marking adds a load index and speed rating after the size, for example 295/35R20 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 295/35R20
Going up one wheel size, the closest match is 275/35R21 at +1.6% diameter with a 96 mm sidewall instead of 103 mm. Going down one size, 285/40R19 is -0.5% with a taller 114 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 295/35R20 tire?
28.1 inches (715 mm) in overall diameter: the 20-inch wheel (508 mm) plus two 103 mm sidewalls. Real tires land within about 1 to 2 percent of that depending on brand, tread depth and pressure.
What is 295/35R20 in inches?
28.1 x 11.6 R20: 28.1 inches tall, 11.6 inches wide, on a 20-inch wheel. The sidewall is 4.1 inches and the circumference is 88.4 inches, so the tire turns 717 times per mile.
What tire sizes are equivalent to 295/35R20?
Within 3 percent of the same diameter on the same 20-inch wheel: 285/35R20 (-1.0%), 305/35R20 (+1.0%), 275/40R20 (+1.9%); on a 21-inch wheel: 275/35R21 (+1.6%), 285/35R21 (+2.6%); on a 19-inch wheel: 285/40R19 (-0.5%), 295/40R19 (+0.6%). The percentage is the diameter change, which is also your speedometer error.
Can I use 305/35R20 instead of 295/35R20?
Dimensionally yes: 305/35R20 is 1.0% taller (+7 mm) and 10 mm wider, and at a true 60 mph the speedometer would read 59.4 mph. The extra width needs about 0.20 in of clearance on each side of the tire and a rim width that suits 305 mm.