Tire Sizes, What Do All Of The Numbers and Letters Mean

Auto Tire Sizes

Like everyone who drives a car, you have had to replace your tires as they wear out. You look on the side wall of your tire and see numbers like P185/70 R 14 88 T or  P235/50 R 18 101 W.  The chart below shows what the second example’s number will tell you.

P23550R18101w
Passenger VehicleWidth =
235 mm		Height =
118 mm		Radial TireRim Width is 18″ Wide825 kg
per Tire		270 km
per Hour
Usage CodeWidthHeightConstructionRim WidthLoadSpeed
The second column is the width of the tire in millimeters. The third column is the percentage of the tire width, which gives the tire height. (235/100×50=118 mm) The fifth column is the rim diameter where the tire bead sits, measured in inches.
Auto Tire Construction

Usage Code

P = Passenger Vehicle
LT = Light Truck
C = Light Commercial
T = Temporary

Radial Construction

R = Radial Type
B = Bias Belt / Cross Ply
If no letter = Cross Ply

Load Capacity Code (KG per Tire)

80 = 450
81 = 462
82= 475
83 = 487
84 = 500
85 = 515
86 = 530
87 = 545
88 = 560
89 = 580
90 = 600
91 = 615
92 = 630
93 = 650
94 = 670
95 = 690
96 = 710
97 = 730
98 = 750
99 = 775
100 = 800
101 = 825
102 = 850
103 = 875
104 = 900
105 = 925
106 = 950
107 = 975
108 = 1000

Speed Rating (Per KM per Hour)

J = 100
K = 110
L = 120
M = 130
N = 140
O = 150
P = 160
Q = 170
R = 180
S = 190
T = 200
U = 210
V = 240
W = 270
Y = 300