Tire Load Range Decoder

This decoder works by matching the load range letter to its ply rating and maximum inflation pressure. Load range letters appear on LT and ST tires.

1. Enter the letter, for example E.
2. Read the ply rating: 10.
3. Read the maximum pressure: 80 psi (552 kPa, 5.52 bar).
4. Compare with the vehicle's placard pressure for loaded use.

The formula is a table lookup: Ply Rating = 2 × (Letter position + 1), starting at B = 4.

Ply rating describes strength, not the actual count of plies. Modern radial LT tires reach a 10-ply rating with fewer real layers. Worked example: load range D is an 8-ply rating at 65 psi (448 kPa).

The conversion table lists 7 load range letters from B to H with ply rating and maximum pressure in psi, kPa and bar. Pressures rise by 15 psi (103 kPa) per letter from C upward.

Load range E is the most common rating on 3/4-ton and 1-ton pickups.

The Tire Load Range Decoder is a tool that explains the letter marking for light truck and trailer tire strength. Load range replaced the older ply rating label, but both still appear on many sidewalls.

A higher load range carries more weight at a higher pressure. At full pressure with a light load, it rides stiffer.

This decoder has 4 uses: towing upgrades, payload checks, ride-comfort choices and trailer tire selection.

• Upgrade for towing: Move from C to E for heavy trailers.
• Check payload: Confirm capacity for loaded beds.
• Balance ride comfort: Avoid an E range for a light-duty truck.
• Select trailer tires: Match ST load range to trailer weight.