315/35R20 Tire Size in Inches

28.7" tall, 12.4" wide, 4.3" sidewall

Diameter28.7"729 mm
Overall diameter28.7"729 mm
Section width12.4"315 mm
Sidewall height4.3"110 mm
Circumference90.1"2289 mm
Revolutions per mile703437 per km
Wheel diameter20"≈ 28.7x12.4R20 in inches

A 315/35R20 tire is 28.7 inches (729 mm) tall and 12.4 inches wide. The sidewall is 35% of the width, 4.3 inches, on a 20-inch wheel, and the tire turns about 703 times per mile.

In flotation terms that is about 28.7x12.4R20. People often call it a 29-inch tire.

The size most often compared with it is 325/35R20, which is 0.3" taller (+1.0%). At an indicated 60 mph you would be doing 60.6 mph on it.

315/35R20
325/35R20
Diameter difference+0.96%diameter 28.68" → 28.96"
CurrentNew
CurrentNewDifference

Speedometer

ShowsActual speed

Gear ratio to match

–enter your current axle ratio

Sizes near 315/35R20

Same 20" wheel, within 20 mm of width and 10 points of aspect ratio.

SizeDiameterWidthSidewallvs 315/35R20
325/35R2029.0"12.8"4.5"+1.0%
295/35R2028.1"11.6"4.1"−1.9%
295/40R2029.3"11.6"4.6"+2.1%
305/40R2029.6"12.0"4.8"+3.2%
315/40R2029.9"12.4"5.0"+4.3%
305/30R2027.2"12.0"3.6"−5.1%
295/30R2027.0"11.6"3.5"−6.0%
295/45R2030.5"11.6"5.2"+6.2%
305/45R2030.8"12.0"5.4"+7.4%
315/45R2031.2"12.4"5.6"+8.6%

Same height on a different wheel

Sizes within 2% of 28.7" on 18" or 22" wheels.

SizeDiameterWidthSidewallvs 315/35R20
275/50R1828.8"10.8"5.4"+0.5%
295/45R1828.5"11.6"5.2"−0.8%
265/50R1828.4"10.4"5.2"−0.9%
295/30R2229.0"11.6"3.5"+1.0%
255/35R2229.0"10.0"3.5"+1.2%
265/30R2228.3"10.4"3.1"−1.5%

Speedometer with a different size

Actual speed when the speedometer is calibrated for 315/35R20.

Speedometer showson 325/35R20on 295/35R20on 295/40R20
30 mph30.3 mph29.4 mph30.6 mph
45 mph45.4 mph44.1 mph46.0 mph
60 mph60.6 mph58.8 mph61.3 mph
70 mph70.7 mph68.7 mph71.5 mph

315/35R20 FAQ

How tall is a 315/35R20 tire?

28.7 inches (729 mm). The sidewall is 4.3 inches.

How wide is a 315/35R20 tire?

12.4 inches (315 mm) section width, measured sidewall to sidewall.

What is 315/35R20 in flotation size?

About 28.7x12.4R20.

Can I use 325/35R20 instead of 315/35R20?

325/35R20 is +1.0% in diameter, within the common 3% guideline. It is 0.4" wider.