Calculation methodology

Weight calculators use pounds internally unless a tool explicitly states otherwise. Displayed metric values use 1 kg = 2.2046226218 lb. Water uses 8.34 lb per US gallon or approximately 1 kg per litre.

Core towing formulas

Payload used = driver + passengers + vehicle cargo + hitch hardware + loaded tongue or pin weight + accessories + miscellaneous.

Trailer loaded weight = documented unloaded weight + options + batteries + propane + water + cargo + supplies.

Remaining margin = entered manufacturer rating − estimated or measured load. “Near” begins at 90% of an entered rating as a conservative planning notification, not a manufacturer threshold.

Combined estimate = estimated loaded tow vehicle + estimated loaded trailer − tongue weight already carried by the vehicle.

Scale-derived hitch load = connected tow-vehicle axle total − tow-vehicle-only axle total when vehicle contents remain unchanged.

Limits

Missing inputs produce a cannot-evaluate result. Calculated estimates never increase a rating. A mathematical margin cannot evaluate stability, braking, tire condition, installation, maintenance, road conditions or laws.