Why the tow rating usually isn't the number
Ford's 2026 towing guide computes maximum trailer weight assuming "no cargo, tongue load of 10%... and driver and passenger (150 lbs. each)." GM's guide uses the same two-people-no-cargo basis. That's the brochure number. Your truck (with the family, the dog, the firewood, and a weight-distributing hitch) is a different truck. Every pound of that, plus the trailer's tongue weight, comes out of one budget: the payload number on your door sticker.
Worked example
And when the answer isn't over across the whole range, when 10% squeaks under but 15% doesn't, this tool won't guess. It says result depends on actual tongue weight, and sends you to the scale page, because a split like that is exactly the case where estimating cannot settle the question and weighing can. Estimates plan, scales measure.
What this tool refuses to do
It won't estimate your truck's ratings from its make and model. Options change the sticker, so we ask for your sticker. It won't turn a green light on from estimates. There are no green lights here at all. And it won't say "safe" or "legal," because a payload check can't see tire condition, axle loads, hitch setup, or the wind. The honest product is a list of which ratings you've checked, which you've exceeded, and which you haven't measured yet.
The yellow placard, and what it actually says
Federal Motor Vehicle Safety Standard No. 110 (49 CFR 571.110) requires a placard on vehicles of 4,536 kilograms (10,000 pounds) GVWR or less, and it specifies the sentence printed on it: "The combined weight of occupants and cargo should never exceed XXX kilograms or XXX pounds." On most pickups that placard is a yellow-and-black sticker on the driver's door jamb or the door edge itself, sitting near the larger certification label that lists GVWR and the front and rear GAWRs. The number after "exceed" is the whole budget. Everyone in the cab, the cooler, the firewood, the generator, the toolbox, the hitch hardware bolted to the receiver, and the share of the trailer's weight that presses down on the hitch all draw from that one figure. Nothing refills it.
Two details trip people up. First, the placard belongs to the individual vehicle it is stuck to, as built and optioned — two trucks wearing identical badges on the same dealer lot can carry different numbers, which is why this tool asks you to read yours rather than guessing from make, model and trim. Second, the placard is a statement about weight and nothing else. It certifies no particular load as appropriate, and neither does anything on this page.
When the truck has no placard: two fallbacks, ranked
That FMVSS 110 placard requirement is scoped to vehicles of 10,000 pounds GVWR or less. Heavier trucks sit under a different regime (FMVSS 120) and may carry no occupants-and-cargo placard at all. Owners of one-ton-and-up trucks routinely hunt the door jamb for a payload figure that was never required to be printed there. This tool offers two substitutes, and they are not equivalent.
Preferred: GVWR minus a loaded scale weight. Weigh the truck with every person and every item aboard and the trailer disconnected, then subtract that reading from the GVWR on the certification label. What remains is the room still available for tongue or pin weight and anything else you add later. Because the occupants and cargo are already sitting on the scale, the tool deliberately does not ask you to enter them again in this mode; counting the same pounds twice is one of the easier ways to talk yourself into a wrong answer.
Fallback: GVWR minus published curb weight. Curb weight is defined in 49 CFR 571.3 as the vehicle with its fluids and standard equipment but no occupants and no cargo, so in this mode occupants and cargo must be entered separately. The result is an estimate, and the tool labels it as an estimate permanently. It never matures into a measurement. A published curb weight describes a configuration; your truck describes itself. Bed liners, running boards, aftermarket bumpers, winches, the fuel actually in the tank and the accumulated sediment of the back seat all live in the gap between the two. Estimates plan, scales measure.
What each rating in the stack actually constrains
The acronyms are not interchangeable, and clearing one of them tells you nothing about the others. 49 CFR 571.3 defines GVWR as "the value specified by the manufacturer as the loaded weight of a single vehicle": one vehicle, everything aboard. The same section defines GAWR as "the load-carrying capacity of a single axle system, as measured at the tire-ground interfaces," and there is a separate figure for the front and for the rear. A truck can sit comfortably under its GVWR while the rear axle exceeds its own rating, because hitch load arrives behind the rear wheels and levers weight off the front. GCWR covers "the loaded weight of a combination vehicle" — tow vehicle plus loaded trailer together, which Ford's guide phrases as the "maximum allowable weight of the towing vehicle and the loaded trailer."
The hitch system carries two ratings of its own, a gross trailer weight rating and a tongue or pin rating, and the governing value is whichever link in the chain is rated lowest: receiver, ball mount, ball, weight-distributing hitch, or fifth-wheel head. A 12,000-pound receiver behind a 5,000-pound ball is a 5,000-pound hitch. These are all separate tests with separate arithmetic, which is why the output below the button is a list of individual checks instead of a single indicator light. There are no green lights on this site.
Tongue and pin weight: the number that quietly eats the payload
NHTSA's towing publication (DOT HS 809 433) describes tongue weight as "the amount of the trailer's weight that presses down on the trailer hitch." A fifth-wheel or gooseneck does the same thing at the kingpin, over the bed instead of behind the bumper. Wherever it lands, it is cargo riding on the truck. Ford's 2026 towing guide states that the "addition of trailer tongue load weight and weight of passengers and cargo cannot cause vehicle weights to exceed rear GAWR or GVWR." GM's 2025 guide says the same thing, naming RGAWR, GVWR and the hitch's own maximum tongue load. Federal label language for motor homes compresses the point into one clause: the tongue weight of a towed trailer counts as cargo (49 CFR 571.110 S9.3.4(e)).
How much is it? The authorities publish bands, not points. For conventional bumper-pull trailers, GM's guide and CURT both give roughly 10 to 15 percent of loaded trailer weight, while Weigh Safe gives 9 to 15 percent. For fifth-wheel and gooseneck pin weight, two manufacturers publish the same band independently: GM’s trailering guide gives 15 to 25 percent, and Ram’s body builder guide says the kingpin weight "should be more than 15 percent and less than 25 percent of the maximum trailer weight." The RV Safety & Education Foundation gives the same 15 to 25 percent, and etrailer describes roughly 20 percent as typical. Ford is the dissent worth knowing about: its older guides carried the same band, but its current ones assume a flat 15 percent, so a Ford owner reading a factory number is reading the bottom of everyone else’s range rather than the middle of it. Ford and Ram also rate trailers at a 10 percent conventional tongue load for testing purposes, which is a test assumption: related to, but not interchangeable with, an operating recommendation. This page evaluates the entire band rather than averaging it away, because the average is the one value your particular trailer almost certainly does not have. The real figure depends on how the trailer was built and how you packed it, and only a scale reports it.
Shaving tongue weight to escape a payload shortfall is not a repair. NHTSA states plainly that "too little tongue weight can cause the trailer to sway," and Weigh Safe and CURT publish the same warning in their own words. Sway is not a comfort complaint; it is how control of a combination gets lost. The honest responses to an overage are less total weight, a different trailer, or a different tow vehicle.
A worked example, one line at a time
The example above compresses several steps. Here is the same arithmetic unpacked, using the figures this page suggests in its own input fields: a placard of 1,614 lb, 780 lb of occupants and truck cargo, 100 lb of weight-distributing hitch hardware, and a bumper-pull trailer evaluated at its 7,600-lb GVWR.
Step 2 — what the tongue asks for. A bumper-pull trailer at 7,600 lb, evaluated across the published 10–15% band, presses down somewhere between 760 lb and 1,140 lb.
Step 3 — compare, at both ends. At the 10% end, 760 lb against 734 lb of room is 26 lb short, displayed rounded up as 30 lb over. At the 12.5% midpoint it is 216 lb short, displayed as 220 over. At the 15% end, 1,140 lb against 734 lb is 406 lb short, displayed as 410 over. Over at every point in the band, so the verdict is OVER A RATING rather than a question about where in the band the trailer actually falls.
Step 4 — the number people actually want. Running the same arithmetic backwards, 734 lb of remaining budget supports a trailer of roughly 4,890 lb if the tongue runs at 15%, or 7,340 lb if it runs at 10%. The tool prints that span and calls it a mathematical planning limit, not a towing rating, because it is derived only from the payload line and ignores every other rating on the page.
Step 5 — and even then. Suppose the payload line had come back clear. The vehicle's maximum loaded trailer rating, the hitch gross trailer rating and the hitch tongue rating are all blank in this example, so the verdict would read INCOMPLETE, not a pass.
Why a blank becomes "not checked" instead of a pass
Leave the hitch tongue rating empty and this tool does not skip past it. It records NOT ENTERED — NOT CHECKED against that line and withholds any non-overage verdict entirely, reporting INCOMPLETE instead. That behavior is deliberate and occasionally irritating. A calculator that reads missing information as the absence of a problem produces its most confident-sounding answers precisely when it knows the least, and in this subject matter that failure mode has a physical consequence. Blanks become "not checked," never "assumed fine."
Four entries gate every verdict other than an overage: an available payload figure, your vehicle's own maximum loaded trailer rating, the hitch system's gross trailer rating, and the hitch system's tongue or pin rating. Occupant weight is required as well, because an empty occupants box is not the same claim as an empty truck. One more guard applies: if you enter a measured tongue weight taken at a real load but then ask the page to evaluate a hypothetical maximum-load scenario, the result is downgraded, since a measurement taken at a lighter load cannot describe a heavier one.
Reading the four verdicts
- OVER A RATING
- At least one value you entered exceeds a rating you entered, at every point in the tongue-weight band. The checks list names which comparison failed and by how much, with overages rounded up rather than down.
- INCOMPLETE — no passing verdict available
- A required rating or input is missing, so the arithmetic cannot be completed. This is neither a pass nor a failure; it is a statement that the question was not answerable with what was provided.
- RESULT DEPENDS ON ACTUAL TONGUE/PIN WEIGHT
- No overage appears at the low end of the published band, and one does appear at the high end. The page will not choose a point inside the band on your behalf. Only a scale resolves it.
- NO OVERAGE FOUND IN THE CHECKS COMPLETED
- The strongest statement this site will ever make, and narrower than it reads. It means the specific comparisons that were completed turned up no value above its stated rating. It is not a finding that the combination is safe, suitable or compliant, and it is silent about every check that was not run.
What this page never looked at
The "not yet verified" list under your result is not decoration. A payload comparison is blind to most of what determines how a combination behaves once it is moving: front and rear axle weights against their individual GAWRs, the load carried by each tire against its own rating and inflation pressure, side-to-side balance, trailer axle and trailer tire loads, brake condition and controller adjustment, weight-distributing hitch tension and setup, coupler engagement, safety chains, load securement, tire age, suspension condition, weather, grade, and the driver. None of that appears anywhere on this page, and no amount of arithmetic can supply it.
Even weighing has blind spots. The Escapees SmartWeigh program warns that a platform scale reading an axle as a single unit can give a false "safe" indication when one side is loaded more heavily than the other, and recommends individual wheel-position weighing for exactly that reason. If the purpose-built instrument carries that caveat, an estimate typed into a web form obviously cannot clear it. That is the whole reason the wording here stops at "no overage found in the checks completed." PLANNING CHECK ONLY — NOT PERMISSION TO TOW. It is not safety certification, legal advice, or permission to tow; your door-jamb labels, your owner's manual, your hitch documentation and your own judgment remain the authority.
Frequently asked questions
Can my truck tow this trailer? The advertised tow rating rarely answers that question, because manufacturers calculate it assuming an essentially empty truck: Ford's and GM's guides both assume only a driver and front passenger at 150 pounds each and no cargo. In practice the binding limits are usually the door-sticker payload (which trailer tongue weight consumes), the rear axle rating, and the hitch system's own ratings. A useful check compares your actual loaded weights against each of those listed ratings, and treats anything unmeasured as unverified rather than assumed fine.
How much tongue weight will my travel trailer have? Authorities publish ranges, not one number: GM and CURT suggest roughly 10–15% of loaded trailer weight for conventional trailers (Weigh Safe cites 9–15%), and 15–25% for fifth-wheel kingpin weight, a band published independently by both GM and Ram. Actual tongue weight depends on how the specific trailer is built and loaded. The only way to know yours is to weigh it, which takes two passes at a truck-stop scale.