Tire Load Index to Weight Calculator
Convert a tire’s load index to its maximum load in pounds and kilograms, and see the total load a full set of four can safely carry.
How it works
Load index → max kg from the ISO/ETRTO load-index table · Pounds = kg × 2.20462 · Set total = per-tire × tires
The two- or three-digit load index stamped after a tire’s size code maps to a specific maximum load in kilograms through a standardized ISO/ETRTO table — for example index 100 equals 800 kg. Converting to pounds and multiplying by the number of tires gives the theoretical maximum the set can support, which should comfortably exceed your vehicle’s gross weight. Never fit tires with a lower load index than the vehicle calls for, and remember the rating only holds at the tire’s specified inflation pressure.
Worked example
A tire marked 100 has a load index of 100, which the standard table lists as 800 kg — about 1,764 lb. A set of four therefore supports roughly 3,200 kg, or about 7,055 lb, at the rated inflation pressure.
Sources: Tire load index (Wikipedia)
Frequently asked questions
What does the tire load index mean?
It is a coded number for the tire’s maximum load-carrying capacity at its rated pressure. Each index value corresponds to a fixed weight in a standardized table — for instance 91 is 615 kg and 100 is 800 kg. A higher index means a stronger tire.
Where do I find the load index on my tire?
It is the two- or three-digit number right after the tire size and before the speed-rating letter — in 225/45R17 94Y, the load index is 94. Match or exceed the index your vehicle placard specifies.
Can I fit tires with a higher load index?
Yes — a higher index is fine and simply provides more capacity. Going lower than the vehicle’s specified index is unsafe and can overload the tire. Note that the rated load applies only at the correct inflation pressure.
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