Reading and converting tire sizes from inches to metric and vice versa can be confusing. Let's take a random motorcycle tire and ATV/UTV tire as examples below.
Metric Size Tires
Metric tire sizes are the most commonly used globally, measured in millimeters. Except for the Rim Diameter, it remains measured in inches.
Metric tire size example: 200/55ZR18
200 = Width
55 = Aspect Ratio (means 55% of the width, 200 in this example) often referred to as Height
18 = Rim Diameter
Additional Specs and Terms on Motorcycle Tires:
Z = Speed Rating
R = Radial Construction
TT = Tube Type
TL = Tubeless
WW = White wall
M/C = Motorcycle
Motorcycle Tire Speed Rating Table
|
Code |
Speed |
|
J |
62 mph |
|
K |
68 mph |
|
L |
75 mph |
|
M |
81 mph |
|
N |
87 mph |
|
P |
93 mph |
|
Q |
99 mph |
|
R |
106 mph |
|
S |
112 mph |
|
T |
118 mph |
|
U |
124 mph |
|
H |
130 mph |
|
V |
149 mph |
|
W |
168 mph |
|
Y |
186 mph |
|
Z/ZR |
149+mph |
Inch Measured Tires
Used in the United States predominantly on ATV and UTV tires and Light Truck (LT) tires also known as “flotation” or "numeric," sizes, or "wide base”.
Example tire size: 29 X9-14
29 = Diameter or often referred to as Overall Height
9 = Width
R = Radial
14 = Rim Diameter
Some heavy-duty tire size format will not show the diameter, only the width and rim diameter. In which case, the size representation will be 9.00x14.
9 = Width
14 = Rim Diameter
Additional Specs and Terms on ATV/UTV Tires:
PR = Ply Rating
| B | 4 ply |
| C | 6 ply |
| D | 8 ply |
| E | 10 ply |
| F | 12 ply |
Take a look at our inventory of motorcycle tires and ATV/UTV tires
