Tyre load capacity guide
What determines a tyre load capacity?
A tyre load capacity is set by the combination of its load index (a code from 62 to 121+ stamped on the sidewall) and the inflation pressure it is inflated to. The load index number maps to a maximum weight per tyre — for example, load index 91 = 615 kg. However, that maximum only applies at the rated inflation pressure (usually 36 PSI / 2.5 bar for passenger cars). Under-inflation reduces load capacity: a tyre inflated to 80% of its rated pressure carries only about 85% of its rated load. Exceeding the load rating causes heat build-up, tread separation, and risk of sudden blowout.
- A tyre load capacity is set by the combination of its load index (a code from 62 to 121+ stamped on the sidewall) and the inflation pressure it is inflated to.
- The load index number maps to a maximum weight per tyre — for example, load index 91 = 615 kg.
- However, that maximum only applies at the rated inflation pressure (usually 36 PSI / 2.5 bar for passenger cars).
FAQ
- What determines a tyre load capacity?
- A tyre load capacity is set by the combination of its load index (a code from 62 to 121+ stamped on the sidewall) and the inflation pressure it is inflated to. The load index number maps to a maximum weight per tyre — for example, load index 91 = 615 kg. However, that maximum only applies at the rated inflation pressure (usually 36 PSI / 2.5 bar for passenger cars). Under-inflation reduces load capacity: a tyre inflated to 80% of its rated pressure carries only about 85% of its rated load. Exceeding the load rating causes heat build-up, tread separation, and risk of sudden blowout.
- What should I verify before using this information?
- Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.
Try a load index
Type the number printed before the speed letter, such as 91V or 94W.
- kg per tire
- 615
- lb per tire
- 1,356
Reference-table value only. Always match your vehicle placard and tire sidewall markings.
How to read the load index on your tyre
The load index is the two- or three-digit number after the tyre width and aspect ratio in the tyre size marking. For a tyre marked 205/55 R16 91H, the load index is 91 and the speed rating is H. The load index maps to a maximum weight per tyre at rated inflation pressure:
| Load index | Max load (kg) | Max load (lb) |
|---|---|---|
| 71 | 345 | 761 |
| 75 | 387 | 853 |
| 80 | 450 | 992 |
| 84 | 500 | 1,102 |
| 87 | 545 | 1,201 |
| 91 | 615 | 1,356 |
| 94 | 670 | 1,477 |
| 97 | 730 | 1,609 |
| 100 | 800 | 1,764 |
| 103 | 875 | 1,929 |
| 106 | 950 | 2,094 |
| 109 | 1030 | 2,271 |
| 112 | 1120 | 2,469 |
| 116 | 1250 | 2,756 |
| 121 | 1450 | 3,197 |
For the full table see our dedicated Tire load index chart.
How inflation pressure affects load capacity
Tyre load capacity is not fixed — it varies with pressure. The rated load index assumes the tyre is at its specified maximum cold inflation pressure. At lower pressures the tyre sidewall deflects more, generates more heat, and can carry less weight safely:
| Inflation pressure | Approx. load capacity (% of rated) | Notes |
|---|---|---|
| 1.5 bar (22 PSI) | ~70% | Dangerously low — tyre sidewall buckles under load |
| 1.8 bar (26 PSI) | ~80% | Low — reduce load or risk blowout |
| 2.0 bar (29 PSI) | ~87% | Below spec — acceptable for light use only |
| 2.2 bar (32 PSI) | ~93% | Slightly below spec — common temporary tolerance |
| 2.5 bar (36 PSI) | 100% | Nominal rated pressure — full rated load |
| 2.9 bar (42 PSI) | 110%+ | Higher capacity — used for XL/Reinf tyres at heavy load |
| 3.5 bar (51 PSI) | 120%+ | Commercial / van XL tyre operating range |
Standard (SL) vs XL / Reinforced tyres
A tyre marked XL or REINF (reinforced) on the sidewall is designed to operate at higher inflation pressures and can carry approximately 10% more weight than a standard load (SL) tyre of the same size and load index number. This matters when fitting an XL-spec tyre to a car that originally used SL tyres — you must inflate the XL tyre to the higher XL pressure to achieve the higher load rating, otherwise it only matches the SL load at the SL pressure.
| Tyre type | Maximum rated pressure | Typical use | XL available? |
|---|---|---|---|
| Standard (SL) | 2.5 bar (36 PSI) | Passenger cars | No |
| XL / Reinforced (XL or REINF) | 2.9 bar (42 PSI) | SUVs, heavy saloons, vans | Yes — load index 10% higher than SL equivalent |
| C (Commercial / Light Truck) | 4.0 bar+ (58+ PSI) | Vans, LCVs, light trucks | N/A — separate rating system (ply rating) |
Calculating your vehicle's required load capacity
To find the minimum load index needed per tyre:
- Find your vehicle's Gross Vehicle Weight Rating (GVWR) — on the door jamb sticker or in the owner's manual.
- Divide GVWR by 4 (for 4 tyres) — or by 2 for the heaviest axle if your vehicle is unevenly loaded (rear-heavy van, towing).
- Add a 10–15% safety margin above that calculated value.
- Find the load index whose kg value is equal to or above that result.
Example: A 1,800 kg GVWR passenger car needs at minimum 450 kg per tyre (1800 ÷ 4). Load index 80 = 450 kg exactly. A load index of 84 (500 kg) is recommended for the safety margin.
Single vs dual (twin) fitment
On commercial vehicles and some vans, rear axles use twin-mounted tyres (two side by side per side). In dual fitment, each tyre carries a slightly reduced maximum load compared to its single-tyre rating, because the sidewalls heat differently and air circulation is restricted between the tyres. Typically the dual load is about 88–91% of the single rating. Always check the specific dual load rating printed in the tyre's load data table or the manufacturer's catalogue.
Signs that your tyres are being overloaded
- Abnormal tyre heat after short drives
- Tyre bulge on the lower sidewall (tyre appears to sag)
- Unusual tread wear — centre wears faster than shoulders
- Increased braking distance
- Handling feels vague or the steering pulls to one side
- Rapid pressure loss after highway driving
If you suspect overloading, reduce the load immediately and have the tyres inspected. A tyre that has been severely overloaded may have internal damage not visible from outside.
More tools
- Load index chart
- Tire pressure guide
- EU tyre label guide
- Tire tread depth guide
- Tire size calculator
- Tire & wheel reference guides
Seasonal check
Planning a long summer drive?
Use the budget and running-cost tools before a trip, especially if the current tyres are worn or the replacement size changes diameter.
What changed
- Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.