How it works
The pin weight of a fifth wheel (or gooseneck) is the share of the trailer’s weight carried by the truck through the kingpin. The accepted range is 15% to 25% of the loaded trailer weight:
Minimum pin weight = loaded weight × 0.15
Typical pin weight = loaded weight × 0.20
Maximum pin weight = loaded weight × 0.25
If you enter your truck’s remaining payload, the calculator checks the pin weight against it. When you have not measured pin weight, it plans for the worst case of 25% so you are not caught short.
Worked example
A fifth wheel weighs 12,000 lb loaded. The truck has 2,800 lb of payload left after passengers, cargo and the hitch.
- Range: 1,800 lb (15%) to 3,000 lb (25%); typical 2,400 lb.
- Worst case: 3,000 lb is 200 lb more than the payload left.
- Weighing shows a real pin weight of 2,450 lb (20.4%), leaving 350 lb of payload.
Pin weight chart
Expected pin weight for common loaded fifth wheel weights.
| Loaded fifth wheel | 15% | 20% | 25% |
|---|---|---|---|
| 8,000 lb (3,629 kg) | 1,200 lb | 1,600 lb | 2,000 lb |
| 9,000 lb (4,082 kg) | 1,350 lb | 1,800 lb | 2,250 lb |
| 10,000 lb (4,536 kg) | 1,500 lb | 2,000 lb | 2,500 lb |
| 11,000 lb (4,990 kg) | 1,650 lb | 2,200 lb | 2,750 lb |
| 12,000 lb (5,443 kg) | 1,800 lb | 2,400 lb | 3,000 lb |
| 13,000 lb (5,897 kg) | 1,950 lb | 2,600 lb | 3,250 lb |
| 14,000 lb (6,350 kg) | 2,100 lb | 2,800 lb | 3,500 lb |
| 15,000 lb (6,804 kg) | 2,250 lb | 3,000 lb | 3,750 lb |
| 16,000 lb (7,257 kg) | 2,400 lb | 3,200 lb | 4,000 lb |
| 18,000 lb (8,165 kg) | 2,700 lb | 3,600 lb | 4,500 lb |
| 20,000 lb (9,072 kg) | 3,000 lb | 4,000 lb | 5,000 lb |
Matching a truck to a fifth wheel
Payload is almost always the first limit you hit with a fifth wheel. A 3/4-ton truck may tow a 14,000 lb trailer on paper, but a 3,000 lb pin plus a 200 lb hitch and four passengers can push it over GVWR. Work through it in this order:
- Find the truck’s real payload with the payload calculator.
- Estimate loaded pin weight here, using 20–25% if you have not weighed it.
- Check the combined weight with the GCWR calculator.
- Check the rear axle rating on the door label: most of the pin weight lands on it.
Common mistakes
- Trusting the dry pin weight. Front storage, batteries and a full fresh tank add a lot.
- Forgetting the hitch weight. The fifth wheel hitch and rails count against payload too.
- Using the 10–15% bumper-pull rule. Fifth wheels carry far more on the truck.
- Overlooking the rear axle and tires. Check GAWR and the tire load ratings on the truck, not only GVWR.