Use the worksheet to find questions—not permission to tow.

Informational planning only

HitchMargin provides arithmetic based on values supplied by the user. It is not engineering, legal, mechanical, dealer, or professional towing advice. A result does not certify a vehicle-trailer combination, its equipment, condition, loading, handling, braking, or legal compliance.

User-entered values are not authenticated

HitchMargin does not know whether an entered rating belongs to the exact vehicle, whether the vehicle has been modified, whether a trailer is loaded as described, or whether a scale reading is current. The user is responsible for matching and verifying every value.

Vehicle lookups provide identity, not verified ratings

VIN and year/make/model responses use manufacturer-reported identity data returned by NHTSA vPIC. A decode may be incomplete or include warnings. HitchMargin does not treat that response as proof of towing capacity, payload, GCWR, axle ratio, receiver rating, or installed tow equipment. A manufacturer source link, missing-range notice, or list of unresolved checks is not a rating or approval.

API beta

Public API access is provided as a revocable beta with no uptime, completeness, or fitness guarantee. Callers must preserve the input, source, and limitation labels and may not represent a mathematical result or identity response as a HitchMargin certification or verified rating.

Not every safety factor is calculated

Depending on the fields entered, checks may omit front axle load, tire ratings, brake requirements, hitch-mode restrictions, frontal-area limits, weight-distribution setup, load stability, road grade, altitude, weather, maintenance, local law, and manufacturer-specific instructions. Missing checks are not approvals.

Stop conditions

Do not tow as entered when any rating is exceeded. When a critical rating or configuration is unresolved, obtain the correct document or professional inspection rather than choosing a favorable estimate.

Third-party names and links

Manufacturer names are used only to identify official source resources. HitchMargin is independent and is not sponsored, approved, or endorsed by those manufacturers or linked services.