Guide
The words on the door label, and where every number comes from.
Ramp Day only does arithmetic on your numbers. This page says what each rating means and which source each rule of thumb came from.
The ratings
Definitions from NC DEQ's "Safe Trailering & Towing" (Division of Marine Fisheries staff training):
- GVWR
- Gross Vehicle Weight Rating: "the maximum safe weight of your vehicle." Ramp Day counts the vehicle, people, cargo and the tongue against it.
- GCWR
- Gross Combined Weight Rating: "the maximum safe weight of your combined vehicle and trailer." Ramp Day counts the vehicle, people, cargo and the whole loaded trailer.
- GTW
- Gross trailer weight: "the weight of the trailer, the boat, motor, gas, equipment, etc."
- Tongue weight
- "The weight of the coupler on the ball when the trailer is fully loaded and level."
- GAWR
- Gross Axle Weight Rating, "usually given as 2 numbers": front and rear. Ramp Day does not split the load between axles; weigh the vehicle on a scale to check it.
"Towing capacity is a 'WEAK LINK' system. The weakest link in the system determines the legal and safe capacity." NC DEQ's worked example: a 3/4 ton Suburban rated to tow 9,600 lb, on a receiver rated 12,000 lb with weight distribution but only 5,000 lb and 600 lb tongue weight-carrying, could tow "a gross trailer weight <5000 lb. and tongue weight <600 lb."
Receiver hitch classes
| Class | Trailer (lb) | Tongue (lb) |
|---|---|---|
| 1 | 2,000 | 200 |
| 2 | 3,500 | 350 |
| 3 | 5,000 | 500 |
| 4 | 12,000 | 1,200 |
Table as printed by NC DEQ. Classes are typical; the label on your receiver wins, and Rig Check uses the class only when no label number is entered.
Tongue weight: two published ranges
- NC DEQ: "at least 10% of the Gross Trailer Weight and should not exceed 15%". Too little "can result in poor handling or even violent trailer movement (fishtailing)"; too much makes the vehicle "work much harder" and may affect front-end handling. "Most trailer winch stands can be adjusted to move forward or back to adjust the tongue weight."
- BoatTest (Justin Hoffman, "How to Measure Boat Trailer Tongue Weight", 27 June 2023): "The recommended trailer tongue weight for boat trailers falls within a range of 5 percent to 7 percent"; single axle about 6%, dual axle about 5%. A bathroom scale at hitch height can measure a light tongue; a municipal scale gives the gross weight.
The two disagree. Rig Check shows where a measured tongue falls against both, and uses 10% (NC DEQ's minimum) only as a planning figure for the hitch checks until you weigh it. Your trailer maker's figure decides.
Weights per gallon
- Gasoline: "approximately 6.2 lbs. per gallon" (NC DEQ).
- Diesel: 7.1 lb per gallon. This is Ramp Day's own figure: diesel is commonly quoted at about 7 to 7.1 lb, and the higher is used.
- Fresh water: 8.34 lb per US gallon (3.785 litres at about 1 kg each).
Ohio law, quoted
- ORC 4513.20(A)(4)(a) (effective 30 June 2007): every trailer "with an empty weight of two thousand pounds or more" needs brakes "designed to be applied by the driver of the towing motor vehicle from its cab", applied automatically "in case of a breakaway".
- ORC 4513.20(A)(5): "Every watercraft trailer with a gross weight or manufacturer's gross vehicle weight rating of three thousand pounds or more", "manufactured or assembled on or after January 1, 2008" (the build date, not the model year), "shall have separate brakes equipped with hydraulic surge or electrically operated brakes on two wheels".
- ORC 4513.32: trailers not hitched by a fifth wheel are coupled with stay chains or cables, in addition to the drawbar, strong enough to keep the trailer from parting if the drawbar fails.
- ORC 5577.05 (effective 1 July 2013): width "One hundred two inches, including load"; height "thirteen feet six inches, with or without load"; "Sixty-five feet for any other combination of vehicles coupled together". Larger loads run "in special cases" under rules of the director of transportation.
Read the current text at codes.ohio.gov before relying on it. Other states set their own rules.
Clean, Drain, Dry
The Ohio Clean Marinas program (ODNR Division of Parks and Watercraft, Ohio Coastal Management and Ohio Sea Grant) asks boaters to "clean off all plants, animals and mud from boats and equipment", "drain water from bilges, live wells, ballast tanks and other water-holding areas" and "dry boats and gear completely before entering another waterbody" (as reported 22 June 2026, Great Lakes Landing Blitz).
What Ramp Day does not do
It does not know your vehicle or trailer: every rating is a number you type in. It does not split loads between axles, judge your brakes, or replace a scale. "OK" means only that the numbers you entered are under 90% of the ratings you entered.