Understanding Tire Ply Ratings and Load Range

At one time, you could gauge a tire’s construction and load-carrying capabilities by the number of plies or layers used to make the tire. Those days are long gone. Today’s tires and their load-carrying capacity are calculated by ply ratings and load range. Here’s what those ratings mean, including a tire load range chart, tire ply rating chart, and how to use that information to get the right tires for your needs.

What is a Tire Ply Rating?

A tire ply rating is a measure of the tire’s strength and ability to carry weight. While the term originally referred to the actual number of layers or plies within the tire, modern tire technology uses stronger materials that allow fewer physical layers while still maintaining or exceeding the same strength. In summary, ply ratings are used as a standardized way to indicate tire durability and load capacity.

The Evolution of Tire Ply Ratings

In the early and mid-20th century, tire plies were made using cotton fibers, which were layered to add strength. These fibers were arranged at specific angles to the tread, forming bias-ply and radial-ply tires. Steel wires eventually replaced the cotton, but the number of plies (or layers) in a tire continued to be used to determine its load-carrying capacity when fully inflated.

Fast forward to today, and modern tire plies are manufactured with rubberized textile cords, which are wrapped under the beads of the tire. These advancements allow for the use of fewer plies while still providing equal or greater strength. As a result, we now refer to this measure of strength as the ply rating, and it is often linked to the tire’s load range, which indicates the tire’s load-carrying capabilities.

What is a Tire Load Range?

The load range, found on the sidewall of most tires, is an indicator of the carrying capacity. This rating is then applied to the chart below to indicate the tire’s ply rating or the tire’s overall strength.

How Ply Rating and Load Range Work Together

In the chart above, tire load ranges are arranged from A to G. A is equivalent to a 2-ply rating, while C equals a 6-ply rating. That ply rating (load range), when combined with the tire size, can tell you the load capacity. The higher the ply rating, the higher the carrying capacity.

Before putting a set of tires on your vehicle, ensure the ply rating or load range meets or exceeds the recommendation on your vehicle’s door placard. You can also find that information in your vehicle owner’s manual.

Where to Find Tire Ply Rating and Load Range Information

You can find the tire ply rating and load range on the tire’s sidewall. Look for the construction type, load range (often denoted by a letter, like "C" or "E"), and other tire specifications molded into the rubber. These markings provide essential details that help determine the tire’s strength and load-carrying capacity.

A common place to find these details is near the tire size, where the ply rating and load range are displayed.

Understanding Tire Markings

The numbers and letters found on a tire’s sidewall tell you a lot about the strength and durability of the tire. It will also tell you the size of the tire, the type of vehicle the tire was designed for (P for passenger vehicles, LT for light trucks, and ST for special trailer), along with the construction type (what’s inside the tire), the load index, speed rating, and load range (equivalent ply rating).

Here are some of the more common tire types:

• P = Passenger Vehicles
• LT = Light Trucks
• ST = Special Trailer
• XL = Extra Load
• HL = High Load (great for EVs)
• C = Cargo

Load Index: What It Is and Why It Matters

The load index number indicates how much weight a tire can support based on the following chart. Using that chart, if a tire has a load index of 89, each tire could support up to 1,279 pounds when properly inflated.

LOAD INDEX	LOAD (lbs)	LOAD INDEX	LOAD (lbs)	LOAD INDEX	LOAD (lbs)
65	639	94	1477	123	3417
66	661	95	1521	124	3527
67	677	96	1565	125	3638
68	694	97	1609	126	3748
69	716	98	1653	127	3858
70	739	99	1709	128	3968
71	761	100	1764	129	4079
72	783	101	1819	130	4189
73	805	102	1874	131	4299
74	827	103	1929	132	4409
75	853	104	1984	133	4541
76	882	105	2039	134	4674
77	908	106	2094	135	4806
78	937	107	2149	136	4938
79	963	108	2205	137	5071
80	992	109	2271	138	5203
81	1019	110	2337	139	5357
82	1047	111	2403	140	5512
83	1074	112	2469	141	5677
84	1102	113	2535	142	5842
85	1135	114	2601	143	6008
86	1168	115	2679	144	6173
87	1201	116	2756	145	6393
88	1235	117	2833	146	6614
89	1279	118	2910	147	6779
90	1323	119	2998	148	6944
91	1356	120	3086	149	7165
92	1389	121	3197	150	7385
93	1433	122	3307

LOAD INDEX	LOAD (lbs)
65	639
66	661
67	677
68	694
69	716
70	739
71	761
72	783
73	805
74	827
75	853
76	882
77	908
78	937
79	963
80	992
81	1019
82	1047
83	1074
84	1102
85	1135
86	1168
87	1201
88	1235
89	1279
90	1323
91	1356
92	1389
93	1433
94	1477
95	1521
96	1565
97	1609
98	1653
99	1709
100	1764
101	1819
102	1874
103	1929
104	1984
105	2039
106	2094
107	2149
108	2205
109	2271
110	2337
111	2403
112	2469
113	2535
114	2601
115	2679
116	2756
117	2833
118	2910
119	2998
120	3086
121	3197
122	3307
123	3417
124	3527
125	3638
126	3748
127	3858
128	3968
129	4079
130	4189
131	4299
132	4409
133	4541
134	4674
135	4806
136	4938
137	5071
138	5203
139	5357
140	5512
141	5677
142	5842
143	6008
144	6173
145	6393
146	6614
147	6779
148	6944
149	7165
150	7385

Specialty Tire Markings and What They Mean

If you don’t see a load range or ply rating on the tire sidewall, you might find the letters P, LT, XL, HL, C, or ST. These correspond to ply ratings. P or passenger tires have a 4-ply rating or lower, while an LT light truck tire has a 6-ply rating or higher. If you drive an EV (electric vehicle), you may need HL (High Load) rated tires to carry the extra weight of the batteries. For cargo vans, look for a C to indicate cargo. However, be sure to get tires that can support your vehicle and its overall load-carrying capacity. Not sure what type of tire you need? Get to Les Schwab.

Selecting the Right Tire Based on Load and Ply Ratings

Aside from the size of tires that fit your vehicle, it’s important that the load index and load range or ply rating match up with vehicle manufacturer recommendations and your hauling or towing needs.

If you’re driving a light truck and you regularly tow an 8,000-pound camping trailer, choose a tire with a higher load range. Additionally, the load index should meet or exceed the recommendations for your vehicle. You never know when you might weigh down a vehicle on a long trip or end up towing a trailer across town. The right tires can help keep you in control and retain adequate braking.

Les Schwab Knows Tire Ply Ratings and Load Range

Understanding load index, load range, and ply ratings can help you get the right tires for what you drive and what you plan to haul. Not sure how to translate that information? The professionals at Les Schwab can walk you through the process and help you choose the right tires for your vehicle and needs.