Plain-English answers to the questions behind the numbers, written against the same published manufacturer figures the calculator uses. No estimates dressed up as facts.
GVM is the most your vehicle is allowed to weigh, fully loaded, including you. What it covers, how to find yours, and how it differs from payload and GCM.
GVM limits your loaded vehicle. GCM limits vehicle and trailer together. The difference, and how much payload towing at the maximum really costs.
What drives the cost of a GVM upgrade, pre-rego versus post-rego, what it does not fix, and how to tell whether you need one before you spend anything.
Tow ball weight is roughly ten percent of the trailer's mass and it comes out of your payload. How to estimate it, measure it and check your limit.