Towing Calculators
Hitch class chooser.
Enter the loaded trailer weight and get the lowest hitch class (SAE J684 Class I to V) whose maximum trailer weight covers it, plus checks for tongue weight and your vehicle's tow rating. Runs in your browser; nothing is sent or stored.
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Result
Fill the form and press Calculate.
Pick the lowest class whose maximum trailer weight is at least your loaded trailer weight: Class I up to 2,000 lb, Class II 3,500 lb, Class III 5,000 lb, Class IV 10,000 lb and Class V up to 17,000 lb (SAE J684 load classes). A 6,000 lb trailer needs at least a Class IV. The actual limit is set by the lowest rating among receiver, ball, coupler and tow vehicle.
Worked example
A loaded trailer of 6,000 lb is above Class III (5,000 lb) and within Class IV (10,000 lb), so you need Class IV or higher. Its 720 lb tongue is above the 500 lb many manufacturers allow without a weight-distributing hitch, and 6,000 lb is 80% of a 7,500 lb tow rating.
How it works
Hitch class by maximum trailer weight: I = 2,000 lb (910 kg), II = 3,500 lb (1,600 kg), III = 5,000 lb (2,300 kg), IV = 10,000 lb (4,500 kg), V = 17,000 lb (7,700 kg). Class V is marketed by some manufacturers but was not listed in the 2014 edition of SAE J684, so treat it as a manufacturer rating rather than a formal standard.
The same reference notes that most manufacturers allow 500 lb (230 kg) of tongue weight without a weight-distributing hitch. A class is only a label: the real limit is the lowest rating on the receiver, ball mount, ball and coupler, and your vehicle's tow rating also applies. Fifth-wheel and gooseneck hitches are rated separately by their makers.
Sources opened 2026-10-16: Tow hitch - Wikipedia (load classes, citing SAE J684); Towing - Wikipedia (hitch assembly limits). Planning aid only, not professional, engineering or safety advice. Your vehicle, trailer, hitch and boat manuals and the weight labels on your equipment come first; when in doubt, weigh it at a public scale or ask a qualified professional.
FAQ
What class hitch do I need for a 5,000 lb trailer?
A Class III hitch is rated up to 5,000 lb, so it just covers it. If the loaded weight could exceed 5,000 lb, step up to Class IV.
What are the hitch class weight limits?
Per SAE J684 load classes: Class I 2,000 lb, Class II 3,500 lb, Class III 5,000 lb, Class IV 10,000 lb. Class V is a manufacturer rating up to about 17,000 lb.
Does a higher hitch class let my vehicle tow more?
No. The vehicle's own tow rating and the hitch assembly's lowest-rated part set the limit. A bigger hitch does not raise the vehicle's capacity.
When do I need a weight-distributing hitch?
Many manufacturers allow up to about 500 lb of tongue weight without one. Above that, follow the hitch and vehicle manuals.
What about fifth-wheel or gooseneck trailers?
These use different hitches rated by their manufacturers and are outside the ball-hitch classes used here.