RV Cargo Carrying Capacity Calculator (OCCC, GVWR, Water, Propane, Passengers & Gear)
Work out how much an RV can actually carry: occupant and cargo carrying capacity from GVWR and unloaded weight, less full fresh water and propane, passengers and pets, then what is left for gear and food — with the common upgrades (batteries, solar, generator, bikes) that quietly eat the margin.
How it works
OCCC = GVWR − UVW (as built, incl. options) · remaining = OCCC − fresh water (gal × 8.34 lb) − water heater − propane (lb) − passengers (× 154 lb) − added equipment − waste water carried · margin = remaining − gear · loaded weight = UVW + everything added ≤ GVWR; each axle ≤ GAWR
Every RV has a maximum loaded weight and a dry weight, and the difference — the occupant and cargo carrying capacity — is smaller than buyers expect once water, propane and the things they bolt on are counted. Full fresh water is often the single heaviest item aboard. The yellow OCCC sticker already subtracts full water and propane for motorhomes; for trailers the arithmetic is yours. Running over GVWR is common, invisible until a scale, and hard on tyres, axles, bearings and brakes, which is why this calculator lays the budget out line by line.
Worked example
A travel trailer with a 9,500 lb GVWR and 7,400 lb UVW has 2,100 lb of cargo capacity. Full 48-gallon fresh tank plus a 6-gallon heater is 450 lb, two propane cylinders 40 lb, and 250 lb of added batteries and solar leave 1,360 lb for gear. Loading 900 lb of gear puts it at about 9,040 lb — 95% of GVWR with 460 lb to spare; travelling with the fresh tank a third full would free another 270 lb.
Frequently asked questions
What is the difference between UVW, brochure dry weight and the yellow sticker?
Brochure weights are for a base unit without options and are optimistic. UVW on the yellow sticker is the actual weight of your unit as built, with factory options. Dealer-installed items, batteries (often not included), and anything you add come out of the OCCC.
Does the hitch weight count against the trailer's GVWR?
The trailer's loaded weight (everything in it) must stay under its GVWR; the portion carried by the hitch (10–15% for travel trailers, 20–25% for fifth wheels) also counts against the tow vehicle's payload. Both limits apply at once, and the tow vehicle's payload is usually the tighter one.
Should I travel with a full fresh tank?
Only if you are boondocking on arrival. Water is 8.34 lb per gallon — a 50-gallon tank is over 400 lb — and it sloshes. Most RVers travel with a quarter to a third and fill near the destination, and always dump grey and black before moving.
Related calculators
RV figures are planning estimates. Your coach's data plates (GVWR, GAWR, OCCC), tyre load-inflation tables and appliance ratings govern; weigh the rig loaded at a CAT scale and adjust.