Towing Capacity Margin Calculator

How it is calculated

The tool compares what you tow with the maximum your vehicle is rated to pull. All three weights are in kilograms: towed weight = trailer + cargo, margin = max towing capacity − towed weight and capacity used = towed weight ÷ max towing capacity × 100. Take the maximum from the vehicle's handbook or plate, and the trailer weight as its empty weight. Cargo is the load you put in or on the trailer, and leaving it empty counts as 0. The maximum must be above zero, and the trailer and cargo weights cannot be negative; otherwise no result is shown. A negative margin means you are over the rating, and a used value above 100% means the same. The tool checks only the towing limit. It does not check the car's own payload, the nose weight on the hitch, or the combined weight rating.

Common mistakes

• Entering the trailer's maximum permitted weight as its weight. Use the actual empty weight and put the load in the cargo box, otherwise the load is counted twice or missed.
• Mixing units, such as pounds for the trailer and kilograms for the rating. All three boxes are in kilograms.
• Treating a small positive margin as comfortable. Rated capacity is a maximum, and a margin close to 0 leaves no room for water, gear or a heavier load.
• Forgetting the hitch (nose) weight. This tool checks only the towing limit, while the weight pressing down on the tow bar also counts against the vehicle's own limits.
• Ignoring a negative result. A margin below zero means the setup is over the rated capacity and should not be towed as it stands.