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Tyres load index table
Table summarizes how to read load index codes printed on tyres and more.

Example

There is example symbol, which we can found on the car tire below. We can read from it, that:
  • The tire has 225 mm of width.
  • Its aspect ratio (height divided by width) is 55%. So, it's rather "wide" tire.
  • The tire has radial construction.
  • The tire fits a 17" diameter wheel.
  • The load index of this tire is 97. It means, that its maximum load is 1,610 lb (730 kg). The table showing how to convert load index value into load in kilograms or pounds can be found in the calculator: Tyres codes - load index.
  • Its speed rating is W, which means that we can drive with maximum speed 168 mph (270 km/h). The table showing how to convert speed rating symbol into speed in mph or km/h can be found in the calculator: Tyres codes - speed ratings

Tyres codes - load index

Load index codeMaximum load (weight) [kg]Maximum load (weight) [lbs]
33
115
254
34
117
260
35
121
267
36
125
276
37
128
282
38
132
291
39
136
300
40
140
309
41
145
320
42
150
331
43
155
342
44
160
353
45
165
364
46
170
375
47
175
386
48
180
397
49
185
408
50
190
419
51
195
430
52
200
441
53
206
454
54
212
467
55
218
481
56
224
494
57
230
507
58
236
520
59
243
536
60
250
550
61
257
567
62
265
584
63
272
600
64
280
620
65
290
640
66
300
660
67
307
677
68
315
694
69
325
717
70
335
739
71
345
761
72
355
783
73
365
805
74
375
827
75
387
853
76
400
880
77
412
908
78
425
937
79
437
963
80
450
990
81
462
1,019
82
475
1,047
83
487
1,074
84
500
1,100
85
515
1,135
86
530
1,170
87
545
1,202
88
560
1,230
89
580
1,280
90
600
1,300
91
615
1,356
92
630
1,390
93
650
1,430
94
670
1,480
95
690
1,520
96
710
1,570
97
730
1,610
98
750
1,650
99
775
1,709
100
800
1,800
101
825
1,819
102
850
1,870
103
875
1,929
104
900
2,000
105
925
2,039
106
950
2,090
107
975
2,150
108
1,000
2,200
109
1,030
2,270
110
1,060
2,340
111
1,090
2,400
112
1,120
2,470
113
1,150
2,540
114
1,180
2,600
115
1,215
2,679
116
1,250
2,760
117
1,285
2,833
118
1,320
2,910
119
1,360
3,000
120
1,400
3,100
121
1,450
3,200
122
1,500
3,300
123
1,550
3,420
124
1,600
3,500
125
1,650
3,640

Some facts

We explained below, how to read tire markings. The things you can read from symbol on a tire are:
  • Nominal section width - this is a width of tire in milimeteres.
  • Aspect ratio - this is a relation beetwen tire's high and width in percentages. Less ratio means wider tire. Historically, the most common was the profile 100% (equal width and height), but there are many different ratios popular nowadays like 80, 70, 60, 55 or 50 etc.
  • Tire construction - this parameter says what is internal construction of the tire. Most common symbols are:
    • R - for radial construction. It's the most popular type for cars.
    • D - for diagonal construction. This type of tires is popular for example in agricultural machinery.
    • B - for bias belt construction. This is special hybrid beetwen radial and diagonal construction. We can found this type of tires for example in the motorbikes.
  • Diameter - for example 17'' diameter means that given tire fits a 17" diameter wheel.
  • Load index - this parameter determines the maximum allowed load, which can be handled by single tire safely. It's a two or three digit symbol denoting maximum load in pounds or kilograms. For example load index 97 is related to maximum load of 730 kg (1,610 lb) per single tire. The table showing how to find maximum load in lb/kg (when we know load index) can be found in the calculator: Tyres codes - load index.
  • Speed rating - this parameter determines the maximum speed, which can be applied to the tire safely with load given by load index. In most common case it's a single letter symbol. For example single letter Q means, that maximum allowed speed is 100 mph (160km/h). The table showing how to find maximum speed (when we know the tire speed rating) can be found in the calculator: Tyres codes - speed ratings.

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