Whether you’re towing a trailer or looking to pack your car before moving across the country, it’s a good idea to know exactly how much weight your car can pull or carry. Overloading your vehicle is a safety hazard that can cause an accident and irreparably damage your car. Knowing your car’s Gross Vehicle Weight Rating (GVWR) can reduce that risk.

The Gross Vehicle Weight Rating (GVWR), also commonly referred to as Gross Vehicle Mass (GVM), is the maximum operating weight of your vehicle as specified by the manufacturer. This includes the combined mass of the car itself and all of its additional components, such as fuel, engine fluids, optional accessories, cargo, and passengers. Overloading your car can result in brake failure, broken suspension components, and added strain on the tires or body.

A car’s Gross Vehicle Weight Rating varies by brand, model, and special components or additional add-ons purchased by the owner, so each car will have a unique weight limit depending on those variable factors. You can usually find this information on the small placard attached to your driver’s side door, within the owner’s manual for your vehicle, or sometimes even listed on the automaker’s website.

While your car’s Gross Vehicle Weight Rating dictates its maximum weight capacity, Curb Weight (CW) is how much your vehicle weighs when it is resting on the curb and not moving. This figure does not include any passengers, fuel, or car accessories or add-ons, but simply represents the exact weight of your vehicle.

Once you know your car’s Gross Vehicle Weight Rating and Curb Weight, you can determine its payload capacity, or the amount of additional weight your vehicle can carry and/or pull via trailer. To do this, subtract your Curb Weight from your Gross Vehicle Weight Rating. Here is the exact formula:

Gross Vehicle Weight Rating (GVR) − Curb Weight (CW) = Payload Capacity

Once you determine your car’s payload capacity, be sure that you never exceed it. Before traveling with a heavy load (whether it’s attached to your roof, inside your car, or being pulled along behind you), weigh everything beforehand to reduce your risk of accident or car damage.