Technical Info

When it comes to tyre sizes there are three variations as shown below.

265/65R17 106S

265 = section width in mm
65 = aspect ratio, as a %age
R = tyre construction, radial
17 = rim diameter, in inches
106 = load rating (see below)
S = speed rating (see below)

9.50R16LT

9.50 = width in inches
R = tyre construction, radial
16 = rim diameter, in inches
LT = light truck construction

32×11.50R15LT

32 = diameter of tyre mounted on rim in inches
11.50 = section width, in inches
R = tyre construction, radial
15 = rim diameter, in inches
LT = light truck construction

Speed Ratings

Load Ratings

Symbol	Max Speed km/h
L	120
M	130
N	140
P	150
Q	160
R	170
S	180
T	190
U	200
H	210
V	240

Index Number	Max Load kg
60	250
70	335
80	450
90	600
100	800
110	1060
120	1400
130	1900
140	2500
150	3350
160	4500
170	6000

Overall Diameter Calculator

This device allows you to enter your original fitment tyre size to calculate the diameter of the tyre (that is, the measurement from the top of the tyre to the ground). It will also calculate the rolling circumference. This is important if you are looking for a wider tyre, lower profile or changing rim size, as these figures need to be similar (+/- 2%) so there will be no effect on your speedometer and gearing. You can input a range of different sizes to a suitable size with equivalent diameters and rolling circumferences.

Current Size		R
Sidewall OD	mm
Rim OD	mm		Rolling Circumference
Total OD	mm		mm cm m