Tire Load Index Calculator

About the Tire Load Index Calculator

The tire load index is a numerical code on every tire's sidewall that indicates the maximum weight each tire can carry when properly inflated. It appears in the service description alongside the speed rating — for example, in 225/50R17 94V, the number 94 is the load index.

Load index values range from about 70 (739 lbs) for small car tires to 126 (3,748 lbs) for heavy truck tires. The total vehicle load capacity equals the per-tire load times four (for a standard 4-wheel vehicle).

Choosing tires with an adequate load index is essential for safety. Overloaded tires overheat, wear prematurely, and are at risk of sudden blowouts. Always match or exceed the load index specified by your vehicle manufacturer.

When This Page Helps

If you tow, haul cargo, or have upgraded wheels, you need to verify your tires can handle the load. This calculator quickly converts any load index number to its weight capacity in pounds and kilograms, and calculates the total 4-tire capacity.

How to Use the Inputs

1. Find the load index number on your tire sidewall (typically a 2-3 digit number like 91 or 105).
2. Enter the load index number.
3. View the maximum load per tire in lbs and kg.
4. See the total 4-tire capacity for your vehicle.
5. Compare against your vehicle's gross weight to ensure adequate capacity.

Example Calculation

Tips & Best Practices

• Never install tires with a lower load index than the vehicle manufacturer specifies.
• Check load index when switching to different tire sizes — width and construction affect capacity.
• Tow vehicles and trucks need higher load index tires (100+) for safe towing.
• Load index assumes tires are inflated to the maximum pressure listed on the sidewall.
• XL (Extra Load) tires have higher load capacity at higher inflation pressures.
• Uneven loading (heavy cargo in the rear) stresses rear tires disproportionately.

Common Load Index Values

Load index 85: 1,135 lbs (compact cars). 91: 1,356 lbs (midsize sedans). 94: 1,477 lbs (crossovers). 100: 1,764 lbs (SUVs). 105: 2,039 lbs (trucks). 110: 2,337 lbs (heavy trucks). 116: 2,756 lbs (commercial). 120: 3,086 lbs (heavy commercial).

Load Index and Vehicle Types

Economy cars: 75–85. Midsize sedans: 88–95. SUVs and crossovers: 95–105. Pickup trucks: 105–120. Commercial vans: 112–126. Heavy-duty trucks use Load Range ratings instead.

Calculating Total Vehicle Load

Your vehicle's GVWR (Gross Vehicle Weight Rating) should not exceed the combined load capacity of all four tires. Subtract the vehicle's curb weight from the total tire capacity to find your maximum payload.

When Load Index Matters Most

Towing and hauling heavy loads. Switching to aftermarket wheels with different tire sizes. Carrying full passenger loads plus cargo. Driving on hot roads (heat reduces effective load capacity).

Frequently Asked Questions

• What load index do I need?

  Check the tire information placard on your driver's door jamb. It lists the required load index and inflation pressure. Never go below that number. Higher is acceptable and provides a safety margin.

• What is an XL tire?

  XL (Extra Load) tires are reinforced to carry more weight at higher inflation pressures. They are rated 3–4 load index points higher than standard tires of the same size. SUVs and crossovers often require XL tires.

• How is load index different from load range?

  Load index is a passenger tire standard (a number like 94). Load range is a light truck standard (letters like C, D, E) indicating ply rating and pressure capacity. They measure the same thing — weight capacity — but use different scales.

• Does tire pressure affect load capacity?

  Yes. The load index rating assumes the tire is inflated to its maximum recommended pressure. Under-inflated tires have reduced load capacity and are at higher risk of failure under heavy loads.

• What happens if I overload my tires?

  Overloading causes excessive heat buildup, accelerated wear, poor handling, and increased blowout risk. Sustained overloading can cause sudden tire failure, especially at highway speeds.

• Do all four tires need the same load index?

  On standard vehicles, yes. Some trucks with staggered sizes may have a higher rear load index for cargo. Always follow manufacturer specifications. Mismatched load ratings can cause handling imbalances.