Six towing calculators in one place: check every tow-vehicle limit at once, compute tongue weight from CAT scale readings, estimate fifth-wheel pin weight, get a weight-distribution-hitch recommendation, browse real trailer weights, and see how fresh-water tanks shift your tongue weight.
Enter your truck's door-sticker numbers and the trailer's GVWR to find your real towing capacity — the binding limit, not the brochure number. The lab checks max tow rating, GCWR, payload and receiver tongue rating — payload usually binds first, because tongue weight counts as payload.
The binding limit is the smallest of the four — that's your real maximum trailer weight. The 80% line is a comfort guideline (mountains, wind, worn brakes), not a rating.
Weighed your rig? Enter the scale numbers and get your real tongue weight and percentage — this is your hitch-weight calculator, and it also flags max tongue weight against the safe band. Works for any ball-hitch trailer: travel trailer, RV, boat, horse, cargo, dump or utility. Aim for 10–15% (ball) or 15–25% (fifth-wheel/gooseneck).
Weigh pass 1 with WDH spring bars disengaged, or the reading is wrong.
Pin weight = 15–25% of the loaded trailer, sitting in the truck bed. It counts directly against payload and rear GAWR — this is where half-ton trucks get surprised.
A WDH restores front-axle load and levels the rig. It does not increase any rating. Not applicable to fifth-wheel/gooseneck. This weight-distribution-hitch calculator applies the industry thresholds to your numbers.
Typical dry-weight ranges from manufacturer specs, plus a realistic cargo allowance (water, propane, batteries, gear) → loaded estimate. Plan to the loaded number, never the dry weight. Click “Use” to load an estimate into the Tongue Weight Lab.
Ranges are planning estimates for 2024–2026 models — your sticker's GVWR is the authority. Horse/dump/cargo allowances include their typical payloads.
Water weighs 8.34 lb/gal (1 kg/L). A full tank ahead of the axles adds tongue weight; behind the axles it removes it — enough to push you out of the safe band.
Simple mode uses the “rule of thirds” planning heuristic (front +60%, rear −40% of water weight). Lever mode is exact geometry: Δtongue = water × (tank→axle ÷ ball→axle).
Safe tongue-weight ranges by loaded trailer weight. Ball hitches: 10–15% (target ~13%). Fifth-wheel / gooseneck pin weight: 15–25% (target ~20%).
Chart values update with the unit toggle. Always confirm with a real weighing — charts plan, scales decide.
Tongue weight is the downward force the trailer's coupler puts on your tow vehicle's hitch ball. It matters because too little tongue weight is the #1 cause of trailer sway — the dangerous fishtailing that can flip a rig at highway speed — while too much tongue weight overloads your truck's payload, rear axle (GAWR) and hitch receiver.
The industry rule of thumb, echoed by NHTSA and trailer manufacturers: 10–15% of the loaded trailer's weight should sit on the tongue for conventional (ball) hitches, and 15–25% for fifth-wheel and gooseneck pin weight.
Three reliable ways, easiest first:
Always measure loaded as you travel — water, propane, gear included.
Aim for the middle of the band: ~12–13% for ball hitches. The 10% figure is a minimum, not a target — rigs at exactly 10% can still sway in crosswinds or when passed by semis. The 15% end is the practical maximum before you start eating payload and overloading the receiver.
For fifth-wheel and gooseneck, the equivalent band is 15–25% pin weight, with ~20% the sweet spot.
The lab's gauge shows where your measured number falls and flags LOW (sway risk) or HIGH (overload).
Use the 3-pass method (costs one re-weigh fee at most CAT scales):
Enter all five numbers in Mode 2 and the lab computes tongue weight and percentage automatically. If your WDH was engaged on pass 1, the reading is wrong — disengage the spring bars first.
Pin weight is the fifth-wheel/gooseneck equivalent of tongue weight: the downward force on the hitch in the truck bed. Because the hitch sits ahead of the rear axle, a fifth wheel can carry more — the accepted band is 15–25% of the loaded trailer weight.
Pin weight counts directly against your truck's payload and rear GAWR. A 14,000 lb fifth wheel at 20% puts 2,800 lb in the bed — more than many half-ton trucks can legally carry. Mode 3 computes the 15–25% band and checks it against your payload and hitch rating.
General industry guidance — Mode 4 applies it to your numbers:
Size the spring bars to your loaded tongue weight, not the trailer's weight: pick the smallest standard bar rating at or above your tongue weight (600 / 800 / 1,000 / 1,200 / 1,400 lb).
No. This is the most common towing myth. A WDH redistributes tongue weight across the truck's front axle and the trailer's axles, restoring steering and headlight aim — it does not raise your tow rating, GVWR, GCWR, GAWR, or the receiver's max tongue rating. Your limits are whatever the lowest rating says, WDH or not. Some receiver hitches actually list two tongue ratings (dead-weight vs. weight-distributing) — use the right column, and never exceed either.
GCWR (Gross Combined Weight Rating) is the maximum allowed weight of your entire rig: loaded truck + loaded trailer together. Max tow rating is the most the truck can pull under ideal SAE J2807 test conditions.
The catch: a realistic GCWR limit is often lower than the tow rating once you load the truck. Max trailer via GCWR = GCWR − (curb weight + passengers + cargo). And payload usually binds first: every pound of tongue weight comes out of payload. Mode 1 checks all four limits and tells you which one actually binds.
Because tongue weight is payload. A truck rated to tow 9,200 lb might have only 1,500 lb of payload. At 13% tongue weight, a 7,000 lb trailer puts 910 lb on the hitch — plus 500 lb of family and gear, you're at 1,410 lb of a 1,500 lb payload. The trailer is 2,200 lb under the tow rating, yet the rig is nearly overloaded.
Payload-limited math: max trailer ≈ available payload ÷ tongue-weight %. This is why Mode 1 exists — the binding limit is the one that matters.
Typical dry (unloaded) weights: teardrop 1,000–2,000 lb; pop-up 2,000–3,300 lb; small travel trailer (17–21 ft) 3,500–5,000 lb; mid (22–27 ft) 5,000–6,800 lb; large (28–33 ft) 6,500–8,800 lb; fifth-wheel 9,500–15,000 lb. A 20 ft travel trailer typically stickers around 4,000–5,000 lb dry and 6,000–6,500 lb loaded; a 30 ft bunkhouse runs roughly 6,500–7,500 lb dry and 8,500–9,500 lb loaded.
Never tow on the dry weight. Add ~1,200–1,800 lb for water, propane, batteries and gear (more for toy haulers). Mode 5 lists 13 trailer types with dry ranges and realistic loaded estimates — click any row to load it into the tongue lab.
Use GVWR (or a realistic loaded weight) for every safety calculation. Dry weight (UVW) is the trailer as it left the factory — no water, propane, batteries, or your stuff. GVWR is the most the trailer may legally weigh, and it's printed on the federal certification sticker.
The honest middle ground: loaded estimate = dry weight + your actual cargo allowance (water 8.34 lb/gal, propane ~4.2 lb/gal, two batteries ~130 lb, gear). When in doubt, plan to GVWR — it keeps every limit conservative.
Yes — a lot. Water weighs 8.34 lb per gallon (1 kg/L). A full 40-gallon fresh tank is ~334 lb, and where it sits matters: tanks are usually ahead of or behind the trailer axles.
As a planning heuristic (the 'rule of thirds'): a front-mounted tank adds ~60% of the water weight to the tongue, a rear-mounted tank subtracts ~40%. On a 6,000 lb trailer at 12% tongue (720 lb), filling a rear 40-gal tank drops you to ~587 lb (9.8%) — into sway territory. Mode 6 models this, including a precise lever-ratio mode if you know the tank and ball distances.
Not reliably from the VIN alone — the VIN identifies the model, not how your specific truck was optioned (axle ratio, tow package, cab/bed). The numbers that matter are on your driver's door jamb sticker (GVWR, GAWR front/rear) and the tire & loading sticker ('combined weight of occupants and cargo should never exceed X' = your real payload), plus the trailer-towing section of the owner's manual for GCWR and max tow by configuration. Enter those in Mode 1.
Sway starts when tongue weight is too low (under ~10%), then gets worse with: too much speed, crosswinds, passing semis, weight concentrated at the trailer's rear, or a too-short wheelbase tow vehicle.
If sway starts: hold the wheel straight, ease off the gas (don't brake the truck), and apply the trailer brakes manually via the brake controller — that pulls the trailer straight. Then slow down and fix the loading: move cargo forward of the axles and re-weigh. A sway-control device helps but never compensates for <10% tongue weight.
SAE J2807 is the engineering standard behind modern tow ratings: it defines how manufacturers must test maximum towing — including acceleration, grade-climbing (the Davis Dam grade), braking, and sway tests with a real trailer. A truck 'rated' under J2807 was tested to that procedure, which is why ratings from ~2015 onward are more comparable across brands.
Important: J2807 is a rating test, not a recommendation to tow at the maximum. The lab's 80% comfort guideline exists because ratings assume ideal conditions — flat test tracks, not mountain passes in a crosswind.
No — and towing mistakes can be fatal. This lab is a planning tool: it applies the standard 10–15% / 15–25% bands and the GCWR/payload math to numbers you enter. It cannot see your truck's actual configuration, tire ratings, or how you've loaded the trailer.
Before you tow: (1) confirm every rating in your owner's manual and door stickers; (2) weigh the loaded rig at a CAT scale; (3) never exceed the lowest applicable rating; (4) have your hitch installation checked by a professional. If anything here disagrees with your manual, the manual wins.
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