Towing Capacity Calculator
Estimate how much your vehicle can safely tow.
Gross combined weight rating from your manual.
Results update as you type.
How it works
Towing safely starts with knowing how much trailer your vehicle can pull once it is loaded, and this towing capacity calculator works that out from the manufacturer's ratings and your actual load. Enter the gross combined weight rating, the vehicle's curb weight, and the weight of passengers and cargo aboard, and the tool returns the maximum trailer weight you have left. The key insight is that a truck's advertised maximum tow rating assumes a nearly empty vehicle. Every passenger, tool box, and full tank eats into the combined weight budget, so a family and their gear can reduce real towing capacity by several hundred pounds. Working from the gross combined weight rating rather than the headline tow figure gives a far more honest number, which protects your drivetrain, brakes, and tyres and keeps you within legal limits. The method is deliberately conservative and simple. The GCWR caps the total weight of vehicle plus trailer. Removing the vehicle's empty weight and then the weight of everyone and everything you have loaded inside leaves the weight available for the trailer and its contents. This is an estimate for planning, not a substitute for weighing your actual rig at a scale and checking the tongue weight and hitch ratings, but it quickly shows whether a given trailer is realistic before you hitch up. Always confirm the figures against your owner's manual and door-jamb sticker.
towing capacity = GCWR − curb weight − passengers and cargo
The gross combined weight rating, or GCWR, is the maximum your loaded vehicle and loaded trailer may weigh together. Subtracting the vehicle's curb weight, its weight empty, leaves the total load the combination can still carry. Taking away the weight of passengers and cargo already inside the vehicle leaves what remains for the trailer and everything on it. That remainder is the heaviest trailer you can tow without exceeding the manufacturer's combined rating.
Source:GCWR-based towing capacity method
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter gcwr and curb weight.
- 2
Adjust the options
Adjust passengers + cargo if they apply — sensible defaults are already set.
- 3
Read your result
Towing capacity updates instantly as you type — no button to press.
Frequently asked questions
What is GCWR?
GCWR stands for gross combined weight rating, the maximum total weight the manufacturer allows for your fully loaded vehicle and fully loaded trailer combined. It is listed in the owner's manual and sometimes on a door-jamb label. Because it caps the whole rig, it is the correct starting point for calculating how much you can actually tow once passengers and cargo are accounted for, unlike the optimistic headline tow rating.
Why is my real towing capacity lower than the advertised figure?
Advertised maximum tow ratings usually assume a lightly loaded vehicle with only a driver aboard. In practice, passengers, fuel, tools, and cargo all add weight that counts against the gross combined weight rating, leaving less budget for the trailer. A crew of people and their gear can cut usable towing capacity by several hundred pounds, so calculating from GCWR and your actual load gives a much more realistic and safer number.
What is curb weight?
Curb weight is the weight of the vehicle as it sits ready to drive with all standard equipment and fluids, including a full tank of fuel, but with no passengers or cargo. It is the baseline weight before you add people and gear. Subtracting curb weight from the gross combined weight rating shows how much total load the vehicle and trailer combination can carry between them.
Does this account for tongue weight?
No, this calculator estimates maximum trailer weight only. Tongue weight, the downward force the trailer places on the hitch, is a separate limit that should be roughly ten to fifteen percent of the trailer's weight for stable towing. You must also stay within the hitch rating and the rear axle rating. Always check tongue weight and hitch specifications alongside this figure before towing to ensure the whole setup is safe.
Should I tow right up to the calculated limit?
It is wise to leave a safety margin rather than tow at the exact maximum. Loading to the limit strains the engine, transmission, brakes, and tyres, especially on hills or in hot weather, and leaves no room for error in your weight estimates. Staying comfortably below the calculated capacity improves control, reduces wear, and gives a buffer for the extra water, fuel, or gear that trips tend to accumulate.