The quantities
V is the trip-ready unhitched vehicle, with the recorded people, equipment, cargo and fuel. T is the complete loaded trailer. H is static tongue weight measured without WDH tension, or an explicit estimate or range.
In weight-carrying mode: vehicle axle mass = V + H; trailer axle mass = T − H; combined mass = V + T. H already belongs to T. The calculation never adds it to combined mass again.
Two input modes
Composition mode adds only load items marked as not already included in the base. A supplied loaded trailer total takes precedence over dry weight and trailer contents. Scale mode uses steer + drive + trailer axle readings directly and does not add inventory to those measurements.
Matched unhitched and combined readings can establish T. They must represent matching load and equipment states. Static tongue weight is supplied independently. Weight distribution requires actual adjusted axle measurements for exact vehicle axle mass.
Independent limits, explicit missing data
Checks cover door-label payload, vehicle GVWR, GCWR, trailer GVWR, applicable vehicle trailer rating, front and rear GAWR, and trailer/tongue ratings for the receiver, ball mount, ball, and coupler. The selected weight-carrying or weight-distributing component limits apply. A missing component is not silently replaced by a stronger known one.
“Within entered limits” means that specific comparison is within the entered limit. “Exceeds limit” means the complete entered interval is above it. “Not evaluated” identifies missing or incompatible data. “Depends on actual weight” means a range crosses the limit. There is no overall certification or probability score.
Ranges and precision
Low and high mass values are evaluated before display rounding. Derived values share their original inputs, so combined mass is calculated directly from V + T rather than adding independent bounds for V + H and T − H. A boundary equal to the rating is within the entered limit. An interval that reaches across the rating remains conditional.
All comparisons use pounds internally. One pound is exactly 0.45359237 kg. Unit switching changes display units, not the physical values or comparison. Water uses an explicit estimate of 8.34 lb per US gallon; one US gallon is exactly 3.785411784 liters. Fuel and propane require their own mass inputs.
Manufacturer conditions
A configuration table’s trailer rating is conditional on its reference vehicle, loading and equipment. Verify the applicable instructions and enter any documented reduction once. There is no universal driver subtraction. If conditions have not been confirmed, the published trailer-rating check remains unevaluated.
Weight distribution does not create extra factory capacity or an automatic payload discount. A personal reserve is displayed separately from official limits. The smallest remaining known margin is identified, while every unknown constraint remains visible.
What this tool does not establish
It does not evaluate handling, sway, braking distance, mechanical condition, driver skill, state law, or tire compliance. Fifth-wheel, gooseneck, multiple-trailer, and commercial combinations are outside this release. The completeness count describes filled checks only.
Data and formula versions travel with exported reports. Public facts are checked against the source registry; known conflicts and coverage gaps appear in coverage.