About the Calculator
This free 4WD GVM calculator helps Australian drivers estimate remaining payload, axle loads, and vehicle weight using representative vehicle geometry and accessory data.
Unlike generic calculators, this tool accounts for model-specific mounting positions and manufacturer accessory specifications, helping you plan your build without relying on rough averages.
It’s ideal for popular platforms such as the Toyota LandCruiser 200 Series, 79 Series, Y62 Patrol, Prado, and other touring 4WDs.
How this calculator is different
Most online GVM calculators use generic weight assumptions. This calculator goes further by modelling vehicle geometry and specific accessory loads.
- Vehicle-Specific Load Positions: Each vehicle model uses approximate axle distances and mounting points to simulate how weight is distributed across your 4WD.
- Brand & Model Accessories: Accessories are based on database product weights - reducing the need to guess weights or search manufacturer specs.
- Fully Customizable: Every weight input can be manually adjusted, allowing you to match the calculator to your own research or weighbridge validation.
- Realistic Load Transfer: See how accessories affect both total GVM and front/rear axle loads.
Quick Note Before You Start
This calculator uses researched and estimated weights for the selected vehicle and modifications to provide an overall estimate. All values are fully customisable. For any legal, registration, or certification requirements, always confirm using a certified weighbridge or engineer.
Step 1 of 3: Getting Started
No Signup • Free • Quick • Simple
How to Use the GVM Calculator
- 1. Select Your Vehicle
- Choose your Make, Model, and specific Variant (e.g., Toyota LandCruiser 200 Series VX). This loads the factory chassis data, axle limits, and wheelbase geometry.
- 2. Add Your Modifications
- Work through the accessory categories (Protection, Storage, Towing). Select your specific brand and model of gear. The tool automatically calculates the weight and the leverage effect on your axles.
- 3. Input Passengers & Payload
- Don't forget the "invisible" weights. Add the driver, passengers, a full tank of fuel, and any loose cargo or tools in the back.
- 4. Check Compliance:
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Review the traffic light system in the results panel:
- Green: You are legal and within limits.
- Red: You are overloaded. You must remove weight, redistribute the load, or investigate a GVM upgrade.
Built Using Real Vehicle Geometry
Unlike basic calculators, this tool uses vehicle-specific axle positions and mounting locations to accurately model how weight is distributed across your 4WD.
Accessory weights are based on real brand and model data - helping you plan your setup without relying on guesswork or rough estimates.
Why staying under GVM matters
Exceeding your GVM doesn’t just affect legality - it directly impacts safety, handling, and long-term reliability.
- Safety & Handling: Correct weight distribution improves braking, stability, and steering.
- Insurance Compliance: Overloaded vehicles may void insurance coverage.
- Component Longevity: Reduces stress on suspension, chassis, bearings, and tyres.
Who Should Use a 4WD GVM Calculator?
This tool is ideal for touring setups, tradespeople, off-road builds, and anyone fitting accessories such as bull bars, canopies, drawers, roof racks, or towing caravans and trailers.
What makes this GVM calculator different?
This calculator uses vehicle-specific geometry and real brand-based accessory weights. This allows far more accurate axle load and GVM estimates compared to generic calculators. Need more details? Visit our “How the Calculator Works” page.
Do I need to estimate accessory weights?
No. Accessories are selected by brand and model so users don’t need to guess weights or research specifications separately. It is recommended to verify weights with manufacturers specifications before committing to a purchase. See our ”Top Accessories” for accessory selection tips.
Supported 4WD Platforms
Stop guessing with generic calculators. Project GVM includes pre-loaded chassis data, axle limits, and kerb weights for Australia's most popular touring vehicles.
Toyota
- LandCruiser 300 Series (LC300)
- LandCruiser 200 Series (LC200)
- LandCruiser 79 Series (Dual & Single Cab)
- LandCruiser 76 Series Wagon
- Prado 250, 150 & 120 Series
- Hilux (N80 & N70)
- Fortuner
Ford & Nissan
- Ford Ranger Super Duty
- Ford Ranger (Next-Gen & PX Series)
- Ford Everest
- Nissan Patrol Y62
- Nissan Patrol GU (Y61)
- Nissan Navara NP300
Isuzu, Mazda & More
- Isuzu D-MAX (RG & TF)
- Isuzu MU-X
- Mazda BT-50
- Mitsubishi Triton (MR & MQ)
- Volkswagen Amarok (V6 & 4-Cyl)
- RAM 1500 (DS & DT)
* Database updated regularly. Missing your vehicle? Please complete the Contact Us form and we will add the vehicle asap.
Vehicle Weight Glossary
- Tare Mass
- The weight of the vehicle with 10L of fuel and all fluids, but zero passengers or cargo. This is often the "showroom" weight.
- Kerb Weight
- The vehicle ready to drive with a full tank of fuel, but no passengers or payload. (Check your manual, definitions vary by manufacturer).
- Axle Capacity
- The maximum weight a single axle (front or rear) can carry. The sum of Front + Rear Axle limits is usually higher than the total GVM.
Need more details? See our article “Ultimate Guide for 4WD Owners”
Common GVM Questions
What is the difference between GVM and Payload?
GVM (Gross Vehicle Mass) is the maximum legal weight of your vehicle when fully loaded. Payload is the weight you can add to the vehicle (passengers, accessories, fuel, and cargo). Put simply: Curb Weight + Payload = GVM. This calculator helps you see if your payload exceeds the GVM limit.
Does tow ball weight count towards my GVM?
Yes, absolutely. The downward weight of your caravan or trailer on the tow ball (Tow Ball Mass) is considered as vehicle "payload" and acts as a heavy weight on your rear axle. While this tool does not calculate GCM (total combination weight), you can add your tow ball weight as an accessory to see how it affects your GVM and rear axle load.
Does a suspension upgrade automatically increase my GVM?
No. Installing heavier springs or shocks improves load-carrying ability and reduces sag, but it does not legally change your GVM. To legally carry more weight, you must have a certified GVM Upgrade plate fitted by an approved engineer. This calculator is perfect for determining if you need to pursue a GVM upgrade.
Why is Rear Axle Load important?
Many 4WDs exceed their Rear Axle Capacity before they hit their total GVM limit. This happens due to the "cantilever effect" of heavy items behind the rear wheels (like drawers, fridges, spare wheel carriers, and tow ball weight). This tool calculates that leverage to warn you if your rear axle is overloaded.
Need more details? Visit our full FAQ Page