Towing Capacity Calculator

Towing capacity is the maximum weight a vehicle can safely tow. Exceeding it causes brake failure, frame stress, transmission overheating, and loss of steering control. Always calculate the full loaded trailer weight, not just the empty trailer.

The Formula:

Gross Trailer Weight (GTW) must be ≤ Vehicle’s rated towing capacity

Tongue Weight = GTW × 10–15% (must be within vehicle’s tongue weight rating)

Key Definitions:

• GVWR (Gross Vehicle Weight Rating): Maximum weight of the vehicle itself, fully loaded
• GCWR (Gross Combined Weight Rating): Maximum weight of vehicle + trailer + all cargo and passengers
• Tongue weight: The downward force the hitch ball bears (typically 10–15% of GTW)
• Payload: How much the truck bed + cab can carry (directly affects available towing)

What this calculator checks: remaining payload.

A trailer’s tongue weight (10–15% of the loaded trailer) presses down on the hitch and counts against your truck’s payload, right alongside passengers and cargo. Run out of payload and you are overloaded even if the trailer is under the tow rating. This tool works from the door-sticker GVWR:

Remaining payload = GVWR − Curb weight − Passengers − Cargo

Worked Example:

Truck: GVWR = 7,000 kg, Curb weight = 2,500 kg, 2 passengers = 180 kg (90 kg each), Cargo in bed = 200 kg.

Remaining payload = 7,000 − 2,500 − 180 − 200 = 4,120 kg

If your loaded trailer’s tongue weight (say 7,000 kg GTW × 12% = 840 kg) fits inside that 4,120 kg, you are within payload. Note this is a payload check, not the tow rating itself: the trailer must also stay under the max tow rating from your manual, and under the GCWR (vehicle + trailer + everything combined).

Safety Margins by Use:

Practical Tips:

• Weight distribution hitches reduce sway on trailers over 50% of vehicle weight
• Trailer brakes are legally required in most US states for trailers over 1,360–2,270 kg
• Downshift on long descents to use engine braking — trailer weight pushes the vehicle