Trailer Tire Size Chart – Get the perfect size for your trailer tires

Trailer tire sizes are broken into main groups 12 inches and smaller and 13 inches and larger. It’s absolutely necessary to use trailer tires for trailers, and not for cars as they are engineered for different usage. Check the below Trailer Tire Size Chart to find the perfect dimension of the needed tire, and it’s specifications like Load range, Rim width and overall diameter.

Looking for a general tire size chart and guide: check here

Trailer Tire Size chart

8 – 9 – 10 – 12 – Inch Trailer Tire Sizing

Older SizeTire SizeRim WidthLoad RangeOverall Diameter
4.80/4.00-83-3/4 inchB: 590 lbs at 60 psiC: 760 lbs at 90 psi16.1 inches
5.70-83-3/4 inchB: 715 lbs at 50 psiC: 910 lbs at 75 psiD: 1,075 lbs at 100 psi18.1 inches
16.5 x 6.5 – 8165/65-85-3/8 inchC: 800 lbs at 70 psi16.5 inches
18.5 x 8.5 – 8215/60-87 inchC: 935 lbs at 50 psiD: 1,165 lbs at 70 psi18.3 inches
6.90/6.00-94-1/2 inchC: 1298 lbs at 60 psi21.1 inches
205/50-106 inchB: 665 lbs at 30 psi18.3 inches
20.5 x 8 – 10205/65-106 inchB: 910 lbs at 35 psiC: 1,100 lbs at 50 psiD: 1,330 lbs at 70 psiE: 1,650 lbs at 90 psi20.5 inches
4.80-124 inchB: 785 lbs at 60 psiC: 990 lbs at 90 psi20.5 inches
5.30-124 inchB: 840 lbs at 55 psiC: 1,045 lbs at 80 psiD: 1,250 lbs at 105 psi21.9 inches
145/80-124 inchD: 1,220 lbs at 65 psiE: 1,520 lbs at 80 psi21.3 inches

13 – 14 – 15 – 16 – 17.5 Inch Trailer Tire Sizing

Letter SizeMetric SizeRim Width RangeLoad RangeOverall Diameter
A78-13B78-13175/80-134-1/2, 5, 5-1/2B: 1,100 lbs at 35 psiC: 1,360 lbs at 50 psiD: 1,610 lbs at 65 psi24.1 inches
C78-13D78-13185/80-134-1/2, 5, 5-1/2C: 1,480 lbs at 50 psiD: 1,725 lbs at 65 psi24.4 inches
F78-14G78-14205/75-145, 5-1/2, 6, 6-1/2B: 1,430 lbs at 35 psiC: 1,760 lbs at 50 psiD: 2,100 lbs at 65 psi26.3 inches
H78-14J78-14215/75-145-1/2, 6, 6-1/2, 7C: 1,870 lbs at 50 psi26.7 inches
8-14.5MH6 inchE: 2,540 lbs at 85 psiG: 3,070 lbs at 116 psi27.7 inches
F78-15G78-15205/75-155, 5-1/2, 6, 6-1/2B: 1,480 lbs at 35 psiC: 1,820 lbs at 50 psiD: 2,150 lbs at 65 psi27.1 inches
H78-15J78-15225/75-155, 6, 6-1/2, 7C: 2,150 lbs at 50 psiD: 2,540 lbs at 65 psiE: 2,961 lbs at 90 psi28.4 inches
7.00-15LT5, 5-1/2, 6E: 2,403 lbs at 70 psi29.4 inches
235/80-166, 6-1/2, 7, 7-1/2D: 3,000 lbs at 65 psiE: 3,500 lbs at 90 psi30.9 inches
235/85-166, 6-1/2, 7, 7-1/2E: 3,640 lbs at 95 psiF: 3,960 lbs at 110 psi31.6 inches
7.50-16LT6D: 2,590 lbs at 60 psiE: 2,926 lbs at 75 psiF: 3,168 lbs at 85 psi31.8 inches
215/75-17.56-3/4 inchH (single): 4,805 lbs at 123 psiH (dual): 4,540 lbs at 123 psi30.2 inches

Trailer Tire Size Conversion Chart

Old Tire SizeCurrent Tire Size

Trailer tire width size

The trailer tire width refers to the distance from the widest point of a tire’s outer sidewall to the widest point of its inner sidewall; this distance is measured once the tire is mounted on the wheel it is going to be used with.

  • Metric: A three-digit number follows the letters that identify the service type. This number designates the width of the tire in millimeters. For example, if a tire’s size was ST175/80-R13 LRD, the 175 identifies the section width as 175 millimeters.
  • Numeric: The first set of numbers identifies the section width in inches. For example, if the tire size is 4.80 X 12B, then you know the section width is 4.80 inches.

Trailer Load Range Chart

Each Special Trailer (ST) service tire has a rated load range. The appropriate load range is represented by a letter within each tire size – B, C, D, and E. Each letter correlates to the ply rating (a number of tire plies) and load pressure (in psi units) for each ST and LT tire. That tells the maximum weight load tire can handle at its full rated PSI pressure.

  • B – 4 Ply Rating, 35 psi (240 kPa)
  • C – 6 Ply Rating, 50 psi (350 kPa)
  • D – 8 Ply Rating, 65 psi (450 kPa)
  • E – 10 Ply Rating, 80 psi (550 kPa)
Load RangePlyPressure
B435 psi (240 kPa)
C650 psi (350 kPa)
D865 psi (450 kPa)
E1080 psi (550 kPa)

What is the most common trailer tire size?

A common trailer tire size is ST225/75R15, commonly used for travel trailers, boat trailers, pop-up campers and all high-load carrying trailers including utility. ST stands for special trailer and indicates that this tire is designed to be used on a trailer. 225 is the width of the tread in millimeters. 75 is the height of the sidewall represented as a percentage of the tread width. 15 is the size of the rim this tire mounts on. In the case of a 225/75R15, the tire is roughly 9 inches wide, 28 inches tall and mounts on a 15 inch rim.

Can I use car tires on a trailer?

Don’t use car tires on trailers. Trailer tires and car tires have different structures to work with different loads. Especially using a trailer tire on your car, or a car tire on your trailer, could lead to serious accidents. Looking for car tire sizes, check here

Is a wider tire better on a trailer?

Wider tires = more road resistance = more power required to pull = lower MPG while towing. Trailer builders use smaller tires to save weight and cost. The larger your tire, the more of a grip your trailer has on the road. As a tire’s width increases, it covers more surface area on the road.

Picture by Benjamin Zanatta on Unsplash

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