Trailer Tire Load Range Chart

Load ranges B through F, what each one means, and — the part most charts skip — how to work out the per-tire capacity your trailer actually needs.

Reviewed for 2026 against the sources listed at the foot of this page. These are published specifications, not annual figures — the year records when the chart was last checked, not a change in the numbers.

Load range	Ply rating	Typical max cold pressure	Typical use
B	4-ply rated	35 psi	Small utility and light boat trailers
C	6-ply rated	50 psi	Single-axle utility, small campers
D	8-ply rated	65 psi	Tandem utility, mid-size travel trailers
E	10-ply rated	80 psi	Large travel trailers, heavy equipment
F	12-ply rated	95 psi	Heavy commercial and large fifth wheels

Load range is not a weight. This is the single most common mistake made with this chart. A letter tells you the tire's construction strength and its maximum pressure — it does not tell you how many pounds the tire carries, because capacity depends on the tire's size too. Two load range E tires in different sizes carry different loads. The governing number is the maximum load stamped on the sidewall of the specific tire, at its stated pressure.

The same caution applies to the pressure column. Those are the usual figures for each load range, not fixed ones — published maxima vary with manufacturer and tire size. Inflating to a chart number your particular tire is not rated for is overinflation. Read the sidewall.

Where to look. The load range letter narrows your shopping; the MAX LOAD figure stamped on the sidewall is what actually governs capacity.

Verify before you tow. These figures are a planning aid, not professional or engineering advice. Your real limits are the ones printed on your vehicle's door-jamb placard, your trailer's VIN plate, and your owner's manual - and those override anything calculated here. When numbers are close, weigh the rig and go with the more conservative answer.

The formula

Weight on tires = Loaded trailer weight - Tongue weight

Tires on the ground = Number of axles x 2

Load per tire = Weight on tires / Tires on the ground

Required capacity = Load per tire x (1 + margin)

Then buy a tire whose SIDEWALL maximum load meets or exceeds
that figure. Use the load range letter to narrow the search,
not to make the decision.

Worked example

Tandem-axle travel trailer at its GVWR   7,600 lb
Pin/tongue weight                          -990 lb
                                          --------
Weight carried by the tires               6,610 lb

Tires on the ground: 2 axles x 2         =      4
Load per tire: 6,610 / 4                 =  1,653 lb

With a 15% margin:
  1,653 x 1.15                           =  1,900 lb per tire

So you need tires stamped for at least 1,900 lb each. In common trailer sizes that typically lands in load range D or E territory — but confirm against the actual sidewall, because the same letter spans a wide range of capacities across sizes.

Why trailer tires fail

Almost always heat, and heat comes from three things: underinflation, overloading, and speed. They compound — a tire that is 10% underinflated and 10% overloaded is not 20% worse off, it is running far outside what it was designed to shed.

Two practical consequences. First, set pressure cold, before the trailer has moved; a warm tire reads high and tempts you into bleeding out air you needed. Second, age matters independently of tread. Trailer tires frequently time out before they wear out, because a trailer sits still for months and sidewalls degrade from UV and ozone regardless of mileage. Plenty of blowouts happen on tires with excellent tread and a date code seven years old.

Speed, and the 10 psi rule

An ST tire is speed rated to 65 mph under normal load and inflation unless its sidewall says otherwise. Above that, the Tire and Rim Association — the body whose load and inflation tables the manufacturers work from — sets out what has to change:

Speed	What TRA requires
Up to 65 mph	Normal placard pressure and full rated load
66 - 75 mph	Cold pressure +10 psi above the trailer placard figure. Requires a tire carrying a speed symbol.
76 - 87 mph	Cold pressure +10 psi and the load reduced by 10%

Two things about that 10 psi that are easy to get backwards. It buys you nothing in capacity — it is there to manage heat at speed, not to carry more weight. And if your wheel or valve is not rated for the higher pressure, you cannot use the allowance at all: 65 mph stays your limit. The wheel is frequently the component that decides this, the same way it decides whether you can fit a higher load range.

Common questions

What does trailer tire load range mean?

Load range is a letter, B through F, describing how much load the tire's construction can support and the maximum cold inflation pressure it is designed for. B is 4-ply rated at 35 psi, C is 6-ply at 50 psi, D is 8-ply at 65 psi, E is 10-ply at 80 psi, F is 12-ply at 95 psi.

The "ply" figure is historical. A modern radial "10-ply" tire does not contain ten layers - it might have two steel belts and a polyester body ply. The rating means it has the equivalent strength of old ten-ply cotton-cord construction.

How much weight can a load range E tire carry?

There is no single answer, and any chart that gives you one is misleading you. Load capacity depends on the tire's SIZE as well as its load range. An ST205/75R15 load range E and an ST235/85R16 load range E carry very different loads.

The only figure that governs is the maximum load stamped on that specific tire's sidewall, at its stated cold pressure. Use load range to narrow your shopping; use the sidewall to make the decision.

Do I have to run trailer tires at max pressure?

For ST (Special Trailer) tires, generally yes - inflate to the cold pressure stamped on the sidewall. This is the opposite of passenger car practice, where you follow the vehicle placard rather than the tire.

The reason is heat. ST tires only reach their rated capacity at full inflation; underinflated, the sidewall flexes more, builds heat, and heat is what destroys trailer tires. Set pressure cold, before driving - a tire checked warm reads high and tempts you to bleed air out, which is exactly wrong.

Can I put a higher load range tire on my trailer?

Usually yes, and it is a common upgrade - a load range E in place of a D gives more capacity margin and runs cooler at the same load. Confirm the wheel is rated for the higher pressure first, because the wheel has its own limit and it is often the constraint.

What it does not do is raise your trailer's GVWR or its axle GAWR. Those are set by the manufacturer as a system. Better tires remove the tires as your weak link; they do not license you to load heavier.

What does the speed rating on a trailer tire mean?

ST tires are speed rated to 65 mph under normal load and inflation unless the sidewall says otherwise. Exceeding that builds heat the tire was not designed to shed.

There is a published allowance above it. The Tire and Rim Association directs that for 66 to 75 mph, on a tire carrying a speed symbol, cold inflation goes up by 10 psi over the trailer placard pressure; for 76 to 87 mph, 10 psi more AND the load cut by 10%.

Two catches. The extra pressure adds no load capacity - it manages heat. And if the wheel or valve cannot take the higher pressure, the allowance is unavailable and 65 mph remains the limit.

Related tools

Sources

Tire and Rim Association load and inflation tables - the industry reference tying tire size and pressure to load capacity; manufacturers publish per-size tables from it
Tire and Rim Association - ST tire speed guidance - 65 mph normal; +10 psi over placard for 66-75 mph with a speed symbol; +10 psi and -10% load for 76-87 mph; the increase adds no capacity
Maxxis trailer tire specifications - published ST tire load ranges: C at 50 psi, D at 65 psi, E at 80 psi
49 CFR 571.3 - Definitions (GAWR) - axle capacity is measured at the tire-ground interfaces, so tires are part of the rating
NHTSA - Tire safety and maintenance - underinflation and overload as primary causes of tire failure