Payload & Tongue Weight Calculator (USA & Canada)
See how much payload your trailer's tongue weight uses and check GVWR, GCWR, axle and hitch ratings.
Example rig — replace every number with your own.
Towing weight check
Limited by Tongue weight vs hitch rating
assumes tow ball mass = 12.5 % of the trailer
Uses the numbers you enter from your plates and manuals — it can't check them for you. Weigh your loaded rig at a public weighbridge or CAT scale. Rules vary by state and country. Not legal advice.
Payload used = passengers + cargo + added accessories + tongue weight. It must stay under the number on your Tire and Loading Information placard. Then check the loaded truck against GVWR, truck plus trailer against GCWR, and the trailer and tongue against your tow and hitch ratings.
How it's calculated
• Payload used = passengers + cargo + accessories + tongue weight
• Truck loaded = truck weight + passengers + cargo + accessories + tongue weight
• Gross combined weight (GCW) = truck loaded + trailer weight − tongue weight
• Tongue weight % = (tongue weight ÷ trailer weight) × 100
• Largest trailer = lowest allowable weight across tow rating, hitch rating, hitch tongue limit ÷ assumed %, remaining payload ÷ assumed %, remaining GVWR ÷ assumed %, and remaining GCWR
Frequently Asked Questions (FAQ)
Where is my payload number?
On the Tire and Loading Information placard on the driver's door jamb: "The combined weight of occupants and cargo should never exceed …" (required by FMVSS 110).
What tongue weight percentage is right?
GMC: about 10–15 % of the loaded trailer for conventional trailers and 15–30 % for gooseneck and fifth-wheel trailers. Your vehicle and trailer manuals come first.
Does a weight-distribution hitch increase my payload?
No. It moves some of the load between the axles; it does not make the trailer or the tongue weigh less, so the tongue weight still counts against payload and GVWR. Use the CAT-scale calculator to see the effect on your front axle.
Sources
- 49 CFR 571.110 (FMVSS 110) — Tire selection and rims; placard (Cornell LII)
Payload placard sentence; tongue weight counts as cargo
- GMC — Tongue weight
10–15 % conventional; 15–30 % fifth-wheel/gooseneck
Last reviewed: 2026-10-26
Built and maintained by Numberwright. The checks follow the definitions published by motoring bodies, transport departments and vehicle makers listed under Sources. Found a mistake? Contact details coming soon.
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