Available Towing Capacity Calculator

Towing = GCWR − vehicle weight − passengers − payload. Stay 80% of max for safety.

Inputs

From owner's manual / specs.

Conventional: 10-15%. 5th wheel: 20-25%.

Result

Max trailer weight
6,786 lb
Safe (80%): 5,429 lb. Tongue 12%.
  • GCWR14000 lb
  • Curb weight5800 lb
  • Passengers + cargo600 lb
  • Available for tow7,600 lb
  • Tongue weight %12%
  • Max trailer (loaded)6,786 lb
  • Safe (80%)5,429 lb

Step-by-step

  1. Available = GCWR − curb − pax = 14000 − 5800 − 600 = 7,600 lb.
  2. Trailer + tongue = available; tongue = trailer × 0.12; → trailer = available / (1 + tongue) = 6,786 lb.
  3. Stay ≤ 80% (5,429 lb) for braking, hill climbs, headwinds.

How to use this calculator

  • Find GCWR from owner manual.
  • Weigh actual passengers + cargo.
  • Set tongue %.

About this calculator

Manufacturer-rated tow capacity assumes near-empty cabin and zero cargo. Real-world tow = GCWR (gross combined weight rating) minus actual loaded vehicle weight. Tongue weight (10-15% conventional, 20-25% 5th-wheel) is supported by the vehicle so it counts against payload. Always tow 80% of computed max — leaves margin for grades, headwinds, and emergency stopping.

Frequently asked

GCWR = max combined truck + trailer + everyone in them. Tow rating = max trailer alone (with empty cabin). GCWR more conservative.

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