The load index (also known as load capacity rating or LI) tells you how much weight a single tire can carry. It is a two or three-digit number located directly after the tire size on the sidewall – and it helps determine whether a tire-rim combination is permissible for your vehicle. Especially for heavy vehicles like RVs, vans, pickups, and off-roaders, the correct load index is safety-critical. In this guide, you will learn how to read the load index, what load capacity it represents, and how to find the right value for your vehicle.
1. What is the load index?
The load index is a standardized numerical code that indicates the maximum load capacity of a tire – i.e., the highest weight that a single tire can bear at the prescribed inflation pressure. The higher the number, the more load the tire can carry.
You will find the load index directly in the size designation on the tire sidewall. For example: In the designation 255/55 R18 109V, 109 is the load index and V is the speed index. The load index is not a weight in kilograms, but rather a key value that you convert to kilograms using a table.
Important: The load index always refers to one tire. For the axle load, the sum of both tires on an axle is counted accordingly.
2. Load index table: Convert LI to kilograms
The following table shows common load index values and the corresponding load capacity per tire. The values are standardized and apply independently of the manufacturer.
| Load Index (LI) | Load Capacity per Tire | Load Index (LI) | Load Capacity per Tire |
|---|---|---|---|
| 84 | 500 kg | 104 | 900 kg |
| 88 | 560 kg | 105 | 925 kg |
| 91 | 615 kg | 106 | 950 kg |
| 94 | 670 kg | 108 | 1,000 kg |
| 95 | 690 kg | 109 | 1,030 kg |
| 98 | 750 kg | 110 | 1,060 kg |
| 100 | 800 kg | 112 | 1,120 kg |
| 101 | 825 kg | 116 | 1,250 kg |
| 102 | 850 kg | 118 | 1,320 kg |
| 103 | 875 kg | 120 | 1,400 kg |
A tire with an LI of 109 can therefore carry up to 1,030 kg. Four such tires theoretically result in a load capacity of 4,120 kg – provided that the rim and the set air pressure also allow this load.
3. Why the load index is safety-relevant
Choosing too low a load index is not a minor offense. If a tire is continuously loaded beyond its capacity, rolling resistance and heat generation increase – this raises the risk of tire damage, even a blowout. Therefore, the law stipulates that the fitted tires must at least meet the requirements specified in the vehicle documents.
This is particularly relevant for vehicles that are frequently driven fully loaded: RVs, panel van campers, vans, and pickups quickly reach high axle loads. If you also mount heavy all-terrain or off-road tires here, you should carefully check the load index – especially when converting to larger diameters.
4. Which load index does my vehicle need?
You can find the required minimum value in your vehicle documents. Here's how:
- Check Registration Certificate Part I: Fields 15.1 and 15.2 list the factory-approved tire sizes, including load and speed index.
- The CoC paper (Certificate of Conformity) also contains the approved wheel-tire combinations.
- Rule: The load index of the new tire must meet or exceed the prescribed value, but never fall below it.
A higher load index than required is generally unproblematic and even beneficial when loaded. Tires with a reinforced carcass often carry the suffixes XL (Extra Load) or Reinforced and offer a higher load index for the same size – ideal for heavy vehicles.
Matching load index and axle load
To check if a tire fits the axle, divide the permissible axle load by two and compare the result with the load capacity from the load index table:
Example: A permissible rear axle load of 1,700 kg results in 850 kg per wheel. A tire with LI 102 (850 kg) exactly meets this, LI 104 (900 kg) offers a reserve. A tire with LI 100 (800 kg) would, however, be too weak.
Dual load index for van and camper tires (C-tires)
For vans and converted panel van campers, you often encounter Commercial tires with the suffix C (e.g., 235/65 R16C) and a dual load index specification like 121/119. The first value applies to single tires (121 = 1,450 kg per wheel), the second to twin tires (119 = 1,360 kg per wheel), where two tires run closer together and therefore may carry slightly less individually. If you drive a heavy camper or van, you should carefully check which of the two values is decisive for your vehicle – and whether the required load capacity is safely reached even when fully loaded.
5. Load index, speed index, and rim load capacity – don't confuse them
Several values appear around the tire designation that are often mixed up:
| Value | Meaning |
|---|---|
| Load Index (LI) | Maximum load capacity of the tire per wheel (e.g., 109 = 1,030 kg) |
| Speed Index | Permissible maximum speed of the tire (e.g., H = 210 km/h, V = 240 km/h) |
| Rim Load Capacity | Maximum load capacity of the rim according to the manufacturer – a separate value |
Crucially: For a complete wheel, the lower of the two values always counts. If the tire can carry 1,030 kg, but the rim is only approved for 950 kg, the effective load capacity of the wheel is 950 kg. Our guide Calculating Rim Load Capacity explains in detail how to determine and calculate the rim's load capacity yourself.
6. Load index for modifications and registration
If you switch to a different tire or rim size, the new combination must meet your vehicle's load requirements. If the combination is not already covered in the documents or an ABE (General Operating Permit), an inspection by an officially recognized testing center is required. The inspector will check, among other things, whether the load and speed indexes are sufficient. You can read more about this in our guide Registering Rims Successfully with TÜV.
A common mistake in off-road and camper conversions: attention is paid to appearance and size, but the load index is overlooked. Especially heavy complete wheels for vans and motorhomes need a sufficiently high LI. Therefore, always pay attention to the complete designation when purchasing.
7. Load index when buying tires at zrshop
In our tire and complete wheel offers, the load index is part of every size specification. When buying, make sure that the value at least corresponds to the load index required in your vehicle documents – and preferably with a reserve if you frequently carry heavy loads.
- Check tire size: The load index is directly after the size (e.g., 255/55 R18 109V).
- Compare with vehicle documents: Match with fields 15.1/15.2 of the registration certificate.
- Plan for loading: For RVs, pickups, and vans, it's better to choose a higher LI (XL/Reinforced).
You can find suitable sizes in our categories 18-inch tires and 20-inch tires, as well as with the robust all-terrain tires for off-road and heavy loads.
Discover tires with the right load index at zrshop now →
FAQ: Frequently asked questions about the load index
What does the load index on tires mean?
The load index is a standardized code that indicates the maximum load capacity of a single tire. It is a number after the tire size (e.g., 255/55 R18 109V – here, 109 is the load index). The value can be converted to kilograms using a table.
How many kg does the load index correspond to?
That depends on the value: LI 100 corresponds to 800 kg, LI 104 corresponds to 900 kg, LI 109 corresponds to 1,030 kg per tire. The assignment is standardized and applies independently of the manufacturer. A complete conversion can be found in the load index table in this guide.
Can the load index be higher than prescribed?
Yes. The tire's load index may meet or exceed the value required in the vehicle documents, but not fall below it. A higher load index is unproblematic and even recommended for frequent heavy loading.
Where can I find the required load index for my vehicle?
In Registration Certificate Part I (fields 15.1 and 15.2) and in the CoC paper. These documents specify the permissible tire sizes including load and speed indexes.
What is the difference between load index and rim load capacity?
The load index describes the load capacity of the tire, while the rim load capacity describes that of the rim. For a complete wheel, the lower of the two values always counts. Both should therefore match your vehicle's axle load.
Is an XL or Reinforced tire better for RVs?
XL and Reinforced tires have a reinforced carcass and a higher load index for the same size. They are often the right choice for heavy, frequently loaded vehicles such as RVs, vans, and pickups.
Sources
- ETRTO (European Tyre and Rim Technical Organisation) – standardized assignment of load index to load capacity
- Straßenverkehrs-Zulassungs-Ordnung (StVZO) – §36 (Tires and treads), §19 (Modifications to vehicles)
- Zulassungsbescheinigung Teil I – Fields 15.1/15.2 (permissible tires and key figures)