38x13.50R20 tire size in inches

A 38x13.50R20 tire measures

38.0" tall × 13.5" wide

9.00" sidewall on a 20" wheel. 531 revolutions per mile.

38x13.50R20 is a flotation (inch) size: 38 inches tall, 13.50 inches wide, for a 20 inch wheel. The R means radial construction.

38.0"20" rim9.0"13.5" wide
38x13.50R20: 38.0 inches tall, 13.5 inches wide, on a 20 inch rim, drawn to scale

38x13.50R20 specs

Overall diameter (height)38.00 inches (965 mm)
Section width13.50 inches (343 mm)
Sidewall height9.00 inches (229 mm)
Wheel (rim) diameter20 inches
Circumference119.4 inches (3,032 mm)
Revolutions per mile531
Revolutions per kilometer330
Approximate rim width9.5" to 12.0"
Aspect ratio (equivalent)67%

Calculated from the size. Real tires differ by brand, model and tread depth, typically by a few tenths of an inch.

Sizes that can replace 38x13.50R20 on a 20" wheel

These 20" sizes are within 3% of 38x13.50R20's overall diameter, the range most tire shops treat as interchangeable.

SizeDiameterWidthDifferenceReal speed at 60
37x12.50R2037.00"12.50"−2.6%58.4 mphCompare
37x13.50R2037.00"13.50"−2.6%58.4 mphCompare

Same height on other wheel sizes (plus and minus sizing)

SizeWheelDiameterDifference
37x12.50R1717"37.00"−2.6%Compare
37x12.50R1818"37.00"−2.6%Compare
37x13.50R1717"37.00"−2.6%Compare
37x13.50R1818"37.00"−2.6%Compare
37x13.50R2222"37.00"−2.6%Compare

Compare 38x13.50R20 with another size

With 37x12.50R20 tires, when your speedometer says 60 mph you are really going

58.4 mph

37x12.50R20 is −1.00 inches (−2.6%) in overall diameter. That is within the 3% most shops and makers allow.

38x13.50R2037x12.50R20Difference%
Overall diameter38.00"37.00"−1.00"−2.6%
Section width13.50"12.50"−1.00"−7.4%
Sidewall height9.00"8.50"−0.50"−5.6%
Circumference119.38"116.24"−3.14"−2.6%
Revolutions per mile530.7545.1+14.3+2.7%

Questions

How tall is a 38x13.50R20 tire?
A 38x13.50R20 tire is 38.0 inches tall (965 mm), calculated from the size. It is 13.5 inches wide with 9.0 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
What does 38x13.50R20 mean?
38x13.50R20 is a flotation (inch) size: 38 inches tall, 13.50 inches wide, for a 20 inch wheel. The R means radial construction.
How many revolutions per mile does a 38x13.50R20 tire make?
About 531 revolutions per mile, based on a circumference of 119.4 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
What rim width fits a 38x13.50R20 tire?
Roughly 9.5" to 12.0". Check the tire maker's approved rim range for the exact model before buying wheels.
Can I use 37x12.50R20 instead of 38x13.50R20?
37x12.50R20 is −1.00 inches (−2.6%) in overall diameter, so at an indicated 60 mph you would be doing 58.4 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.

Browse