Trailer Tongue Weight and Sway Check
The number that decides whether a trailer tows straight or fishtails, which the gross- and axle-weight tiles never check: tongue% = tongue / gross x 100, against the 10-15% conventional and 15-25% gooseneck/fifth-wheel bands. A 7,000 lb trailer with a 700 lb tongue is at 10.0% (in band, 700-1,050 lb target); shift the load back to a 490 lb tongue (7.0%) and it drops below the floor - the trailer-sway risk the tile flags, fixed by moving cargo forward of the axle. Too much tongue overloads the hitch and unloads the steer axle. A setup screen; the manufacturer ratings and a scale govern.
Formula and source
tongue% = tongue_weight / trailer_gross x 100; target band = 10-15% (conventional) or 15-25% (gooseneck / fifth wheel); target_lb window = gross x band; over_rating when tongue > hitch rating.
Standard towing tongue-weight guidance (NHTSA / SAE J2807; the hitch and vehicle manufacturer ratings), by name.
Audience
This tile is built for truckers and the adjacent professions in the Trucking and Logistics group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
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Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.