Trailer Hitch Classes Explained: Class 1 to 5, Receiver Sizes and Ratings

A hitch class is a capacity band for the receiver hitch itself, the square tube and cross member bolted to the vehicle's frame. Each class comes with a receiver size and two numbers:

• Gross trailer weight (GTW): the most the loaded trailer can weigh.

• Tongue weight (TW): the most downward force the trailer tongue, or a hitch-mounted rack, can put on the receiver.

The class is a label for the range; the hitch's own rating label is what counts. Two Class 3 hitches can carry very different numbers. In the site's guides, the CURT 13493 for the 2021–2026 Bronco is a Class 3 rated 3,500 lb GTW and 350 lb TW, while the Draw-Tite 76527 for the same truck is Class III at 4,500 lb and 675 lb. Both sit comfortably inside CURT's Class 3 range of up to 8,000 lb and 800 lb, and neither comes close to its top.

Naming isn't consistent either. Toyota describes its PK960-42K10 RAV4 hitch as Class II but with a 2 in receiver tube, even though CURT and etrailer both put Class 2 on 1-1/4 in. So read three things on any listing: the receiver size, the GTW and the TW. The class word alone doesn't tell you enough.

There is no single chart that every maker prints. The compare table above shows CURT's and etrailer's published ranges side by side, and they disagree in places:

• Class 2 tongue weight: CURT lists up to 350 lb; etrailer's range runs to 525 lb.

• Class 4 capacity: CURT lists up to 10,000 lb GTW and 1,000 lb TW; etrailer's range goes to 12,000 lb and 1,200 lb.

• Class 5 receivers: CURT splits Class 5 into Xtra Duty on a 2 in receiver (16,000–17,000 lb GTW) and Commercial Duty on 2-1/2 in (18,000–20,000 lb); etrailer lists 2, 2-1/2 or 3 in and a 10,000–25,000 lb range.

The published ranges are summaries of what hitches in each class are usually rated for, not certifications. What matters for your setup is the number stamped on the hitch's label and printed in its instructions, which is the rating the maker tested it to. When a listing gives a class but no GTW and TW, the site's guides treat that as a reason to confirm with the seller.

CURT's class page puts it plainly: towing capacity is always limited to the lowest-rated component, whether that's the hitch, an accessory, the vehicle or the trailer. etrailer says the same thing in fewer words. A hitch never raises what your vehicle can tow.

The site's RAV4 guide shows how wide the gap can be. The fifth-generation RAV4 is rated 1,500 lb on gas LE through Limited trims, 1,750 lb as a Hybrid, 2,500 lb as the Prime, and 3,500 lb on Adventure and TRD Off-Road with the Tow Prep Package, per Toyota dealer figures. The B&W and Draw-Tite hitches listed for it are rated 4,500 lb. Bolting a 4,500 lb Class III hitch to a 1,500 lb XLE still leaves a 1,500 lb tow rating; the extra hitch capacity is margin, not permission.

The Bronco guide makes the same point in the other direction. Ford rates most 2021–2026 Broncos at 3,500 lb and the Raptor at 4,500 lb, so a 3,500 lb CURT hitch matches most trucks while only a 4,500 lb hitch like the Draw-Tite 76527 matches the Raptor.

The chain includes more than the hitch and vehicle. The ball mount, the hitch ball, the coupler, the safety chains and any adapter each carry their own rating. Add them up in your head as the lowest number in the list, not the highest.

Four places, in this order:

1. The owner's manual or the maker's towing guide. These list maximum trailer weight and maximum tongue weight by engine, drivetrain, cab and bed, axle ratio and tow package. Use the line that matches your exact vehicle, not the headline figure for the model. 2. The certification label on the driver's door jamb. It lists the gross vehicle weight rating (GVWR) and the gross axle weight ratings (GAWR). NHTSA's towing guide warns that the rear axle rating on this label must not be exceeded, and tongue weight lands mostly on the rear axle. 3. The tire and loading information placard, also on the door jamb. It gives the most weight of occupants and cargo the vehicle should carry. That is your payload, and trailer tongue weight or a loaded bike rack counts against it along with passengers and gear. 4. The hitch's own label. It gives the hitch's GTW and TW and, where applicable, a separate weight-distribution rating.

The smallest relevant number wins. A half-ton pickup with a full cab of people and a bed of gear can run out of payload before it reaches its advertised tow rating, which is why the door-jamb labels matter as much as the brochure.

Tongue weight is the downward force the trailer puts on the ball. etrailer's guidance is that it should be 10–15% of the loaded trailer's weight: 1,000–1,500 lb on a 10,000 lb trailer, or 300–450 lb on a 3,000 lb one.

NHTSA's towing guide explains why the range matters. Too little tongue weight can make the trailer sway. Too much causes problems of its own, including not enough weight on the tow vehicle's front wheels, which affects steering and braking.

The figure has to fit inside three limits at once: the hitch's TW rating, the ball mount's rating and the vehicle's tongue-weight limit in the owner's manual. On a small SUV the vehicle's limit is usually the one that bites first. Loading heavier items ahead of the trailer axle raises tongue weight; moving them back lowers it. A tongue-weight scale, or a bathroom scale and a lever for light trailers, takes the guesswork out.

NHTSA's guide draws the line clearly. Weight-carrying hitches carry all of the trailer's tongue weight on the receiver and the vehicle's rear axle. That is how every hitch works out of the box. Weight-distributing hitches add spring bars and brackets to a receiver hitch so the tongue weight is spread across all of the tow vehicle's and the trailer's axles, putting weight back on the front wheels.

Many hitches publish two sets of ratings, one weight-carrying and one weight-distributing. In the site's Bronco guide, the CURT 13493 is rated 3,500 lb and 350 lb weight-carrying and 4,000 lb and 400 lb with weight distribution; the Draw-Tite 76527 is 4,500 lb and 675 lb either way. CURT's class chart lists weight-distribution capacity up to 12,000 lb on its Class 3 and Class 4 hitches. Some hitches aren't approved for it at all: the Reese 06192 Class 2 for the RAV4 is not compatible with weight distribution.

A weight-distribution system never lifts the vehicle's own maximum tow rating. What it does is restore steering and braking feel with heavier trailers, and many owner's manuals specify one above a certain trailer weight. Check yours, and only use one on a hitch that lists a weight-distribution rating.

1-1/4 in receivers belong to Class 1 and 2. They tuck under small cars and crossovers and carry light bike racks and trays. CURT's chart tops them out at 3,500 lb and 350 lb.

2 in receivers are the standard for Class 3 and 4 and fit most hitch bike racks, cargo carriers and ball mounts. On most SUVs and pickups this is the size to buy. The site's RAV4 guide recommends 2 in unless you already own 1-1/4 in gear, because brand-name Class III hitches cost about the same as Class II.

2-1/2 in receivers appear on CURT's Commercial Duty Class 5 hitches and on heavy-duty trucks.

A hitch rack is pure tongue weight. etrailer's example: a 200 lb rack with two 50 lb bikes puts 300 lb on the receiver, which can overload some small hitches. Heavy e-bike racks add up quickly, and the further the load sits from the bumper, the more leverage it applies. Weigh the rack and bikes together and compare them to the lower of the hitch's TW and the vehicle's tongue limit before you load.

Adapters look like a cheap way around a receiver-size mismatch. They cost capacity.

• 1-1/4 in to 2 in adapters (a small receiver made to take 2 in gear): CURT says these reduce the hitch or vehicle's tongue weight capacity by up to 50%, leaving a Class 1 hitch at around 100 lb of tongue weight or less, and can cut towing capacity by 30% or more depending on the adapter and setup. A loaded 2 in bike rack on an adapted Class 1 hitch is the classic overload.

• 2 in to 1-1/4 in reducers (a sleeve so small accessories fit a large receiver): etrailer notes these let you carry Class I and II accessories on a larger hitch. The limit is then the accessory's rating.

• Extenders push the load further back to clear a tailgate spare or a rear door, which adds leverage. Treat any extender as reducing capacity, and follow the extender maker's derating.

If you find yourself needing an adapter to run a rack, the better fix is usually the right receiver in the first place.

A trailer needs working lights before it goes on the road, and the hitch doesn't include them.

• 4-way flat connectors carry the ground, tail lights and left and right turn and brake signals. They cover most small utility trailers, bike trailers and light boat trailers. A vehicle-specific plug-in harness such as CURT's 56434 for the RAV4 connects to factory plugs without splicing.

• 7-way connectors add an electric-brake circuit, a 12 V power feed for a trailer battery, and a reverse-light circuit. Campers and any trailer with electric brakes use them.

Factory wiring isn't guaranteed. Ford's own Bronco receiver kit says a wiring harness is sold separately, and the Bronco guide lists Ford's 4/7-pin harness as an extra. Avoid splice-in kits that cut factory wires where a plug-in harness exists, and route the harness clear of the exhaust. Safety chains are the other must: NHTSA's guide says they should cross under the trailer tongue and have enough slack for sharp turns without dragging.

Electric trailer brakes need a controller in the cab that applies them when you brake and lets you apply them on their own to settle sway. Without a controller, a 7-way plug does nothing for the brakes.

When a trailer needs its own brakes is set by state law, usually by trailer weight, and the rules differ. Oregon's version of NHTSA's towing guide, for example, says Oregon law does not require trailer brakes but strongly encourages them. Check your state's rules and your owner's manual, which may require trailer brakes above a certain weight regardless of the law.

Don't assume a factory controller comes with a hitch. Bronco6G owners point out that adding a hitch after delivery doesn't add the brake-controller hardware that comes with Ford's Trailer Tow Package, so budget for an aftermarket unit if you tow a braked trailer. Many trucks with a factory tow package have a controller built into the dash; many SUVs and crossovers don't.