Frequently Asked Questions

GVM stands for Gross Vehicle Mass. It is the maximum legal weight your vehicle can weigh when fully loaded. This includes the vehicle itself, fuel, all accessories (bullbars, winches), passengers, and cargo. Exceeding your GVM is illegal, can void your insurance, and makes your vehicle unsafe to drive.

GVM is the total weight limit of the car. However, your vehicle also has a Front Axle Limit and a Rear Axle Limit. It is possible to be under your total GVM but still exceed the rear axle limit if you pack too much weight in the back. This calculator checks both your total GVM and individual axle loads.

• • Tare Weight: The weight of the empty vehicle with 10 litres of fuel and no occupants.

  • Kerb Weight: Usually defined as the vehicle ready to drive with a full tank of fuel, but no payload or driver.

Note: This calculator starts with the manufacturer's Tare Weight and adds fuel and accessories based on your inputs.

Generally, no. In many cases, it actually reduces it. Most vehicles have a Gross Combination Mass (GCM), which is the total allowed weight of the vehicle plus the trailer. If you increase the weight of the vehicle (by using a GVM upgrade), you often have less "allowance" left over for a heavy trailer.

Weight placed behind the rear axle (like a heavy tow ball weight, spare wheels, or jerry cans) acts like a lever. It pushes the rear down but actually lifts weight off the front wheels. This creates a pivot point that multiplies the load on the rear axle. This calculator automatically calculates this weight transfer for you.

This tool provides a highly educated estimate based on manufacturer specifications and average accessory weights. However, every vehicle is unique due to manufacturing tolerances and specific accessory choices. This tool is for planning purposes; for 100% compliance, you must weigh your vehicle at a certified weighbridge.

This is due to the physics of the wheelbase. When you add weight behind the rear wheels (the "overhang"), it acts as a lever, putting more pressure on the rear axle and lifting weight off the front axle. This is critical for steering and braking safety.

Select "Stock" as the supplier, and then manually edit the Certified GVM, Front Axle Limit, and Rear Axle Limit fields in the "GVM Upgrade" section. The calculator will update the visual diagram based on your custom numbers.

You may be under your total GVM limit, but you have exceeded the load capacity for the rear axle. This is common in dual-cab utes. You can try moving heavy items forward (between the axles), removing accessories, or investigating a suspension upgrade that increases axle capacity.

Yes. By default, the calculator adds 170kg for "Driver & Passenger." You can adjust this in the "Occupants" section to "Driver Only" or specific passenger configurations to get a more accurate result.

If you fit a GVM upgrade after the vehicle has already been registered (Post-Rego), it requires an engineering signatory (compliance plate) relevant to your state. A federally approved upgrade (SSM) usually applies to brand-new vehicles prior to first registration. Always check with your local transport authority.