What size hitch do I need for my trailer?
Hitch class is sized to your loaded trailer weight — and the class chart is only the first of three numbers to check.
Step 1: know the real weight
If you don't have a scale ticket, estimate: dry weight + 12% for a light utility trailer, +30–40% for a camper with water and gear aboard. Then verify with a CAT scale run — $12–15 buys certainty.
Step 2: the hitch class chart
| Class | Max trailer (with WDH) | Max tongue weight | Typical trailers |
|---|---|---|---|
| I | 2,000 lb | 200 lb | Small utility, bike racks |
| II | 3,500 lb | 350 lb | Utility, pop-ups, small boats |
| III | 8,000 lb | 800–1,000 lb | Single-axle campers, boats, equipment |
| IV | 10,000 lb | 1,000–1,200 lb | Travel trailers, toy haulers |
| V | 12,000+ lb | 1,200–1,400 lb | Large campers, livestock |
Class III ratings are commonly two numbers: 5,000 lb weight-carrying, 8,000 lb with a weight-distribution hitch. The receiver is the same; the rating changes with the hardware bolted into it.
Step 3: the ball
| Ball size | Trailer weight | Typical |
|---|---|---|
| 1-7/8" | under 2,000 lb | Small utility, pop-ups |
| 2" | 2,000–3,500 lb | Utility, small campers |
| 2-5/16" | 3,500 lb+ | Nearly all travel trailers |
Match the coupler's stamped requirement, and carry the adjustable dual-ball mount if you tow more than one trailer — a 2"/2-5/16" combo covers everything from utility to camper duty.
Step 4: weight distribution — the line most people miss
Two triggers for a WDH:
- Hard trigger: loaded trailer above ~50% of the tow vehicle's curb weight. A 4,500 lb camper behind a 5,500 lb SUV is at 82% — WDH territory, no exceptions.
- Symptom trigger: wheel wander, trailer sway, or headlight pitch at highway speed — the rear axle is squatting and the front tires have lost steering grip.
A WDH redistributes tongue weight across all four axles with spring bars sized to a bracket: pick bars rated for your tongue weight bracket (e.g. 600–800 lb bars for a 700 lb tongue), not "the biggest ones." Oversprung bars ride harsh and transfer every bump. How to measure the tongue number first: the tongue weight guide.
The hitch is never the only limit
A Class IV receiver on a half-ton truck doesn't make the truck a 10,000 lb tower. Four ratings all bind: the manufacturer's tow rating, the GCWR, the payload (tongue weight + passengers + cargo), and the hitch class — and payload is almost always the binding one. A 1,000 lb tongue against a 1,500 lb payload rating leaves 500 lb for two adults and a cooler. Run all four in the towing calculator before buying hardware.
Everything here is standard stock: Class III/IV receivers, adjustable dual-ball mounts, WDH kits by tongue-weight bracket, and tongue-weight scales for verification.
Reading the rating stickers you already own
Every piece of this system is stamped, and the stamps beat the marketing: the receiver has a weight-carrying and weight-distributing rating on a sticker or stamp on its face; the ball mount has its capacity cast into the shank; the ball itself lists a max gross weight and shank diameter on the box (a 2-5/16" ball is rated 10,000–15,000 lb, a 2" ball 3,500–6,000, a 1-7/8" ball 2,000). The coupler on the trailer lists the ball diameter it demands. Chain them: coupler → ball → mount → receiver, each rated at or above your loaded weight — and the weakest link, not the strongest, is the system's rating.
Two details people miss on used rigs: the receiver may have been on a previous vehicle with different ratings, and hitch bolts loosen — check the torque on the carriage bolts (usually 100–150 ft-lb per the manufacturer) once a season and after any hard sway event. A receiver that's shifted even a quarter inch under load tells you everything; catch it parked, not at 65 mph.
Safety chains are part of the hitch too: cross them under the coupler so a coupler failure lets the tongue ride on the crossed chains instead of plowing the road, keep enough slack to turn but never enough to drag, and use rated S-hooks or shackles — never the spring clips that came with a bike rack.
Everything here is standard stock: Class III/IV receivers, adjustable dual-ball mounts, WDH kits by tongue-weight bracket, and tongue-weight scales for verification. Class III receivers on Amazon · WDH kits on Amazon · tongue-weight scales on Amazon
FAQ
What size hitch for a travel trailer?
Almost all travel trailers need Class III minimum (8,000 lb with WDH), a 2-5/16" ball, and a weight-distribution hitch — the tongue weights (500–1,000 lb) and 50%-of-curb rule put them past weight-carrying limits. Run your loaded weight and tongue through the calculator, then buy hardware to the bracket.
Can my hitch be bigger than I need?
Up to Class III/IV on a vehicle that can handle it, yes — headroom is free capability. But the receiver's rating never raises the truck's: tow rating, GCWR, and payload still bind, and a Class V receiver bolted to a crossover is a Class V number with Class II reality.
Does tongue weight count against payload?
Yes, pound for pound — plus the 75–120 lb the WDH hardware itself weighs. That payload line is where most rigs quietly exceed a rating, which is why the payload math lives in the calculator alongside the class chart.
Next: hardware picks in best hitches & weight distribution, the four-rating explainer in towing capacity explained, and sibling tools at GeneratorSizer ↗, Battery Bank Sizer ↗.