What Is GCWR: Method First, Then the Numbers

What Is GCWR is the number that caps the whole combination: tow vehicle plus trailer, fully loaded. GCWR is the maximum weight of the vehicle and the trailer together, and it is the limit that catches people who check the tow rating but forget the payload. This page explains what GCWR means, how it relates to GVWR, and how to work out whether your combination is inside it.

Never exceed your vehicle's GVWR, GCWR or payload. Check the owner's manual and the door-jamb sticker for the ratings that apply to your exact vehicle, and treat every figure on this page as a worked example unless it comes from your own vehicle's plates.

The method: the lowest of three ratings for what is gcwr

On this page, what is gcwr is the case in point: Start with three numbers and keep the smallest: the vehicle tow rating, the tow-bar rating and the trailer ATM (aggregate trailer mass, the maximum loaded weight the trailer is rated for). The worked example on this page uses a vehicle rating of 6,500 lbs, a tow-bar rating of 7,500 lbs and a trailer ATM of 8,000 lbs, so the capacity is 6,500 lbs — whichever of the three is lowest. Treat those as example figures: your own numbers come from the owner's manual, the tow-bar plate and the trailer plate. The rule is strict because each rating protects something different — the vehicle's drivetrain, brakes and cooling; the tow bar and its fixings; the trailer's running gear — and the combination is only as strong as its weakest part.

There is a second layer of limits behind the tow rating. The loaded vehicle may not exceed its GVWR, the vehicle-plus-trailer combination may not exceed its GCWR, and the payload — the gap between kerb weight and GVWR — has to cover passengers, cargo and the tongue weight of the trailer. That last point is the one people miss: the hitch load is carried by the vehicle, so a heavy trailer shrinks the payload left for everything else. Pass the tow-rating check and still fail GCWR or payload, and the combination is overloaded. Check all three against the figures for your exact vehicle in the manual and on the door-jamb sticker.

what is gcwr: Where to find your ratings

Start with the owner's manual: it lists the tow rating by engine, axle ratio and configuration, and it states the GVWR and GCWR. Then check the door-jamb sticker on the driver's door, which gives the GVWR and the payload for your exact vehicle as built — this is the number that matters, because options fitted at the factory change it. The tow bar itself has a rating plate, usually stamped on the bar or on a label near the receiver, and the trailer has a compliance plate showing its ATM and its tare (empty) weight. If the manual and the sticker disagree, use the lower figure and ask a dealer to confirm for your VIN. Never take a rating from a forum, a sales listing or a figure quoted for a different year or engine: ratings change with engine, axle ratio, cab, bed length and tow package, and the only numbers that count are the ones for your vehicle.

GVWR, GCWR and payload: how they fit together

GVWR is the maximum the loaded vehicle may weigh. GCWR is the maximum the vehicle and the trailer together may weigh. Payload is GVWR minus the vehicle's kerb weight — the weight of passengers, cargo, fuel and tongue weight the vehicle may carry. In this page's example the payload is 1,400 lbs. A trailer of 5,000 lbs puts about 625 lbs of tongue weight on the hitch, which leaves 775 lbs of payload for everything else. That is the check people miss: a vehicle can be inside its tow rating and still overloaded, because the tongue weight plus the family plus the luggage exceeds the payload. Work the payload check every time you load up, not just when you buy the trailer.

what is gcwr: Worked example: the three ratings and the payload check

Take a 5,000 lbs loaded trailer as the example. The vehicle's tow rating is 6,500 lbs, the tow-bar rating is 7,500 lbs and the trailer ATM is 8,000 lbs. The towing capacity is the lowest of the three: 6,500 lbs. The trailer's tongue weight at 10 to 15 percent is 500 to 750 lbs, and the middle of that range — about 625 lbs — is a good target. With an example payload of 1,400 lbs, the tongue weight leaves 775 lbs for passengers and cargo. If the passengers and luggage weigh more than that, the combination is overloaded even though the trailer is inside the tow rating, and something has to come off — either the trailer load or the vehicle load. That is the whole check in one paragraph: lowest of three, then tongue weight, then payload, then GCWR. Do it with your own numbers before every trip, because the answer changes every time the load changes.

Tongue weight table for what is gcwr

The tongue-weight range below is 10 to 15 percent of the loaded trailer weight, with 12.5 percent in the middle as a practical target. Find your trailer's loaded weight in the first column and read across. Weigh the trailer as it will travel — guessing the weight makes the whole table useless. That is the point this page works through for what is gcwr.

Loaded trailer weight (lbs) 10% tongue weight 12.5% tongue weight 15% tongue weight
3,500 350 438 525
5,000 500 625 750
6,000 600 750 900
7,000 700 875 1,050
10,000 1,000 1,250 1,500

The four checks, in order for what is gcwr

Check What to compare Passes when
Tow rating Trailer weight against the lowest of the three ratings Trailer is at or below the lowest rating
Tongue weight Tongue weight against 10–15% of trailer weight Percentage sits inside 10–15%
Payload Tongue weight plus passengers and cargo against payload Sum is at or below payload
GCWR Vehicle + trailer loaded weights vs GCWR Combined weight is at or below GCWR

what is gcwr: Common mistakes

  • Taking what is gcwr as the case in point: Ignoring the GCWR. A combination can be inside the tow rating and still over the GCWR once the vehicle is fully loaded with people and luggage.
  • Forgetting that tongue weight counts against payload. The hitch load is carried by the tow vehicle, so it reduces the passengers and cargo you can carry by exactly that amount. That is the point this page works through for what is gcwr.
  • Taking what is gcwr as the case in point: Skipping the brake check on the trailer. A trailer's brakes need testing before every trip, not just at service time — a seized or disconnected trailer brake puts the whole stopping job on the tow vehicle.
  • Using the trailer's empty weight instead of its loaded weight. A trailer's tare weight is the empty figure; the loaded weight is what the ratings are tested against, and water, gas, luggage and equipment can add hundreds of pounds. That is the point this page works through for what is gcwr.

what is gcwr: Related calculations

On this page, what is gcwr is the case in point: For the next step, these pages apply the same method to a closely related question — or hand the arithmetic to the calculator.

Putting your figure to work for what is gcwr

For what is gcwr, the point is this: Putting the figure to work means doing the check with your own numbers before every trip, not once when you buy the trailer. Weigh the loaded trailer, read the three ratings off your own manual and plates, work out the tongue weight, and check the payload and GCWR. Write the four numbers down and keep them with the trailer's documents: the lowest of the three ratings, the tongue-weight range, the remaining payload and the GCWR headroom. When the load changes — a full water tank, an extra passenger, a different trailer — redo the check, because the answer changes with the load. That habit is what keeps a towing combination inside its limits on the road, not just on paper.

Frequently asked questions

Where do I find my vehicle's tow rating?

For what is gcwr, the point is this: In the owner's manual, listed by engine, axle ratio and configuration, and on the door-jamb sticker and VIN plate for your exact vehicle. The tow bar has its own rating plate, and the trailer has a compliance plate showing its ATM. If the manual and the sticker disagree, use the lower figure and ask a dealer to confirm for your VIN.

What is tongue weight and why does it matter?

On this page, what is gcwr is the case in point: Tongue weight is the downward force the trailer puts on the hitch. It should be 10 to 15 percent of the trailer's loaded weight — for a 5,000 lbs trailer that is 500 to 750 lbs. Too little causes sway; too much overloads the tow vehicle's rear suspension and lightens the steering. Load the trailer to get the percentage right, then re-weigh.

How do I weigh my trailer?

Use a weighbridge for the loaded trailer, or a tongue-weight scale for the hitch load. Weigh it loaded as it will travel — water, gas, luggage and all — because the empty weight tells you nothing about the loaded figure. Divide the tongue weight by the loaded trailer weight to check it is inside 10 to 15 percent. That is the point this page works through for what is gcwr.

Do I need trailer brakes?

On this page, what is gcwr is the case in point: That depends on the trailer's weight and local rules: heavier trailers generally require their own brakes, and the threshold varies by country and by state. Check the trailer's ATM, the tow vehicle's manual and the local regulations. A trailer with brakes stops shorter and puts less load on the tow vehicle's brakes, which is why the braking requirement exists.

How much trailer can I tow?

It depends on the lowest of your vehicle's tow rating, your tow-bar rating and the trailer's ATM, capped by GVWR, GCWR and payload. In this page's worked example the lowest rating is 6,500 lbs. Substitute your own three ratings and run the same check — the answer is specific to your vehicle and your trailer, not a general figure.