Towing Calculator API
Trailer-towing weight maths as an API, computed locally and deterministically. The tongue endpoint computes the tongue (hitch) weight as a percentage of the loaded trailer weight and reports the recommended 10–15 % range — too little tongue weight is the main cause of trailer sway. The capacity endpoint computes the maximum trailer weight a tow vehicle can pull, GCWR − curb weight − payload (the passengers and cargo in the vehicle), and checks a proposed trailer against it with the margin remaining. The payload endpoint computes the vehicle payload still available once the trailer is hitched, GVWR − curb weight − tongue weight, since the tongue weight presses down on the tow vehicle and counts against its payload rating. Everything is computed locally and deterministically, so it is instant and private. Ideal for RV, caravan, trailer and fleet apps, tow-vehicle matching and load-planning tools, and automotive calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. Guidance only — follow the manufacturer's ratings. 3 endpoints. This is trailer-towing weights; for tyre size and rolling circumference use a tyre API.
api.oanor.com/towing-api
