Every load index in lb & kg, speed ratings, LT vs P-metric
| Load Index | Max Load (lb) | Max Load (kg) | Typical Use |
|---|---|---|---|
| 71 | 761 | 345 | Compact spare, small trailer |
| 75 | 853 | 387 | Subcompact cars |
| 76 | 882 | 400 | Subcompact cars |
| 77 | 908 | 412 | Subcompact cars |
| 78 | 937 | 425 | Small cars |
| 80 | 992 | 450 | Small cars |
| 81 | 1,019 | 462 | Small cars |
| 82 | 1,047 | 475 | Sedans |
| 83 | 1,074 | 487 | Sedans |
| 84 | 1,102 | 500 | Sedans |
| 85 | 1,135 | 515 | Sedans, small EVs |
| 86 | 1,168 | 530 | Sedans |
| 87 | 1,201 | 545 | Coupes, small hatchbacks |
| 88 | 1,235 | 560 | Sedans |
| 89 | 1,279 | 580 | Crossovers |
| 90 | 1,323 | 600 | Crossovers |
| 91 | 1,356 | 615 | Crossovers (very common) |
| 92 | 1,389 | 630 | Crossovers |
| 93 | 1,433 | 650 | SUVs |
| 94 | 1,477 | 670 | SUVs |
| 95 | 1,521 | 690 | SUVs (very common) |
| 96 | 1,565 | 710 | SUVs |
| 97 | 1,609 | 730 | Larger SUVs |
| 98 | 1,653 | 750 | Larger SUVs |
| 99 | 1,709 | 775 | Light-duty pickups |
| 100 | 1,764 | 800 | Pickups, minivans |
| 101 | 1,819 | 825 | Pickups |
| 102 | 1,874 | 850 | Pickups, 3-row SUVs |
| 103 | 1,929 | 875 | Pickups |
| 104 | 1,984 | 900 | Half-ton pickups |
| 105 | 2,039 | 925 | Half-ton pickups |
| 106 | 2,094 | 950 | Half-ton pickups |
| 107 | 2,149 | 975 | Heavy half-ton |
| 108 | 2,205 | 1,000 | HD pickups (single rear) |
| 109 | 2,271 | 1,030 | HD pickups |
| 110 | 2,337 | 1,060 | HD pickups |
| 111 | 2,403 | 1,090 | HD pickups |
| 112 | 2,469 | 1,120 | HD pickups |
| 113 | 2,535 | 1,150 | HD pickups |
| 114 | 2,601 | 1,180 | HD pickups |
| 115 | 2,679 | 1,215 | Vans, HD pickups |
| 116 | 2,756 | 1,250 | Cargo vans |
| 117 | 2,833 | 1,285 | Cargo vans |
| 118 | 2,910 | 1,320 | Cargo vans |
| 119 | 2,999 | 1,360 | Dually pickups (rear) |
| 120 | 3,086 | 1,400 | Dually pickups, trailers |
| 121 | 3,197 | 1,450 | LT truck & trailer tires |
| 122 | 3,307 | 1,500 | LT truck tires |
| 123 | 3,417 | 1,550 | Heavy trailer |
| 124 | 3,527 | 1,600 | Heavy trailer |
| 125 | 3,638 | 1,650 | Heavy trailer, RV |
| 126 | 3,748 | 1,700 | Heavy trailer, RV |
The load index isn't linear — it's a lookup table standardized by the ETRTO/Tire & Rim Association, which is why you can't compute it from a formula. Pound values are the kilogram standard × 2.20462, rounded. Max load applies only at the tire's maximum inflation pressure, printed on the sidewall.
| Rating | Max Speed | Typical Fitment |
|---|---|---|
| L | 75 mph | Off-road / trailer |
| M | 81 mph | Trailer, temp spare |
| N | 87 mph | Trailer |
| P | 93 mph | Temp spare |
| Q | 99 mph | Winter studded |
| R | 106 mph | Light truck, winter |
| S | 112 mph | Family sedans, minivans |
| T | 118 mph | Sedans, crossovers (very common) |
| H | 130 mph | Sport sedans, SUVs |
| V | 149 mph | Sports cars |
| W | 168 mph | Performance cars |
| Y | 186 mph | Supercars |
| (Y) | 186+ mph | Extreme performance |
Older "ZR" markings (ZR appears instead of R in the size) mean 149+ mph with no upper bound; W and Y refined that. Ratings certify sustained speed capability under load — a durability and heat standard, not permission.
| P235/75R15 (104S) | LT235/75R15 (C range) | |
|---|---|---|
| Built for | Passenger cars, crossovers | Pickups, hauling, towing |
| Max load | 1,984 lb | 1,985 lb |
| Pressure at max load | 35 psi | 50 psi |
| Derated on trucks/trailers | Yes — ÷1.10 → ~1,804 lb | No derating |
| Sidewall | Softer ride | Reinforced, stiffer |
The trap: the two tires carry the same maximum load on paper, but the P-metric hits its number at 35 psi while the LT needs 50 — and the Tire & Rim Association requires P-metric capacity to be cut 10% when fitted to light trucks, SUVs used for hauling, or trailers. Same size, same load index printed on the sidewall, less usable capacity on a truck. Load range letter (C, D, E) is the LT equivalent of the index, tied to ply construction: B = 4-ply/35 psi, C = 6-ply/50 psi, D = 8-ply/65 psi, E = 10-ply/80 psi, F = 12-ply/95 psi.
Every tire sold in the US carries a service description — the load index and speed rating stamped after the size, like 102H in 225/65R17 102H. The index is a code for the tire's maximum load at maximum pressure; decoding it takes one lookup, and sizing it for a vehicle takes one division.
Decode: look the number up in the chart (or use the calculator). 102 = 1,874 lb per tire; a set of four carries 7,496 lb. Check your vehicle: add curb weight to the weight of everyone and everything aboard, divide by four, and each tire's rating must beat that number. Rule: match or exceed the placard on your door jamb — the manufacturer already did this math with your worst-case load in mind.
Type a service description like 102H or 121S, or pick an index from the dropdown. The vehicle card below takes curb weight (on the door placard or the manufacturer spec sheet) plus your passengers and cargo estimate, and returns the minimum index that clears a quarter of the loaded weight.
A crossover wearing 225/65R17 102H: each tire carries up to 1,874 lb, so four cover 7,496 lb, and H certifies 130 mph. Load it up — 4,400 lb curb plus 1,200 lb of family and gear = 5,600 lb, or 1,400 lb per tire. That requires index 93 (1,433 lb) at minimum, and the factory 102s clear it with 34% headroom (1,874 ÷ 1,400 ≈ 1.34). Downgrade to 91s (1,356 lb) while loaded and each tire runs over its rating — heat builds, sidewalls flex, and blowout risk climbs. On a heavy truck the same math pushes you into LT territory: LT265/70R17 121S = 3,197 lb per tire, 12,788 lb across four, at 50+ psi where the load range demands it.
The load index is the two- or three-digit number in your tire's service description — 102H means load index 102, speed rating H. It encodes the maximum weight one tire can carry at its maximum inflation pressure: 102 = 1,874 lb (850 kg). Multiply by four (or two on a motorcycle) to get the tires' total capacity, which must exceed your vehicle's fully loaded weight.
Add your curb weight to the weight of passengers and cargo, then divide by four — each tire must carry at least a quarter of the gross weight. A 4,400 lb SUV with 1,200 lb of people and gear needs tires rated at least 1,400 lb each, which means load index 93 (1,433 lb) at minimum. Never go below the index printed on your door-jamb placard.
Yes — a higher index is always safe; the tire simply carries more than required, and ride quality usually changes little within one or two steps. Going lower than the vehicle's placard specification is not acceptable. When replacing tires, match or exceed the original load index, and keep all four tires identical.
P-metric (P235/75R15) tires are built for passenger cars and rated at max load around 35 psi; LT-metric tires have reinforced sidewalls for hauling and towing and reach their max load at 45-80 psi depending on load range. In the same size, a P235/75R15 carries 1,984 lb at 35 psi while an LT235/75R15 load range C needs 50 psi to carry roughly the same — and when a P-metric tire is fitted to a truck, trailer, or SUV used for hauling, its capacity must be derated about 10% (1,984 becomes about 1,804 lb).
The letter after the load index is the certified sustained speed capability: T = 118 mph, H = 130 mph, V = 149 mph, W = 168 mph, Y = 186 mph, with (Y) meaning above 186. Most passenger cars ship with T or H; sports cars run V and above. For legal US driving any rating exceeds speed limits — the rating matters for handling feel and heat durability, not daily legality.
Yes. Mixing load indices (or sizes, or speed ratings) means the axles carry different capacities and the vehicle handles unevenly under load or in an emergency maneuver. If you must replace one tire, match the exact size, load index, and speed rating of the other three — or better, replace in pairs and put the new pair on the rear.