TrailerTowCalc

Methodology and editorial standards

How the calculators turn the numbers you type in, where published figures come from, and how to send a correction.

How the calculator works

The calculators run in your browser. The output is a planning estimate, not a measured result. The door-jamb sticker and the owner's manual for that truck govern.

The towing tab takes the tow rating, GCWR, curb weight, payload rating, loaded trailer weight, cargo in the truck, and passengers. A hitch rating is included only when one is entered. Tongue weight for that pass is 12 percent of the loaded trailer. That 12 percent is this calculator's midpoint of CURT's 10–15 percent band, not a separate standard (tongue weight guide). The max safe trailer is the lowest of four caps: the tow rating, GCWR minus the loaded truck (curb weight plus cargo plus passengers), the trailer whose 12 percent tongue fits the payload left after passengers and cargo, and the hitch rating when one is entered. The result names which of those caps governs.

The tongue-weight tab uses a measured percent of trailer weight, or a bathroom-scale reading times the lever multiplier. Under 10 percent it calls the tongue too light. Over 15 percent it calls the tongue too heavy. Otherwise it says the tongue is in CURT's 10–15 percent band, and it prints targets at 10, 12, and 15 percent.

The payload tab adds tongue weight, hitch hardware, passengers, and cargo, then compares that total with the payload rating.

The brake tab prints a starting gain from this site's formula using trailer weight, tow-vehicle weight, and brake type. The homepage does not publish a gain setting or a test speed. Follow the controller maker's instructions and the manuals for the tow vehicle and the trailer.

Where the numbers come from

Ratings you type in come from the door-jamb sticker and the owner's manual. Rules of thumb cited on a page come from the sources linked on that page, including CURT hitch classes, CURT tongue weight, NHTSA towing safety, and SAE J2807_202411.

The 2026 truck towing capacity chart is copied exactly as published. Every row links its source document. The access date is October 6, 2026. Where a guide does not give a figure, the cell says "not listed". Nothing on that chart is estimated.

How pages are written

Page text is drafted with AI agents (Cursor and local models) from those sources. Compiled with AI assistance from the sources on each page.

Built and owned by Jeremy Panasuk, New Auburn, WI.

Jeremy is a data/software person, not a licensed automotive or towing professional. These are planning tools, not professional advice.

Affiliate policy

As an Amazon Associate I earn from qualifying purchases. The Amazon links below are affiliate links; they don't change the math. On pages that have Amazon links, that disclosure sits before the first affiliate link. The tag on those links is generatorsi0d-20. The links never change calculator output. This site does not sell paid placements.

Corrections

Spot an error? Email jpanasuk@gmail.com with the page URL.

Corrections log