Towing Capacity Calculator
Payload, GCWR, tongue weight and hitch limits checked together
Your real towing capacity is the lowest of several limits: GCWR minus the loaded truck, the payload left for tongue weight, the manufacturer's trailer rating and the hitch rating. A truck with a 7,000 lb GVWR, a 5,400 lb curb weight and a 14,500 lb GCWR carrying 650 lb of people and gear can tow 7,916 lb at 12% tongue weight, because payload runs out before GCWR does.
Last updated October 2026
Method: Weight-rating arithmetic based on the federal vehicle labels and NHTSA towing guidance. Payload is GVWR minus curb weight, tongue or pin weight counts as payload (49 CFR 575.6), and truck plus trailer is compared with GCWR. The heaviest trailer is the lowest result across all limits, rounded down to the pound.
Included: Payload left, tongue or pin weight (percent or measured), GVW, GCW, the maximum trailer under each limit, a tongue-weight range check for conventional trailers (10% to 15%, from federal fleet guidance) and a 15% to 25% planning range for fifth-wheel or gooseneck pin weight (GSA's guide puts it at about 25%), and Class I to IV hitch presets.
Not included: Axle loads (GAWR) and tire limits, which need a scale; weight-distribution setup; state brake and permit rules; and model-specific ratings, which come from your owner's manual.
🛻 Your truck, load and trailer
1. Truck ratings
Driver door-jamb certification label
Empty truck with full tank; a scale ticket beats the brochure
Owner's manual or the maker's towing guide
Conventional towing rating for your exact configuration
2. Load in the truck
Use real body weights, not a guess per seat
Bed cargo, toolbox, cap, hitch hardware, pets
3. Trailer
Dry or unloaded weight from the trailer label
Fresh water weighs about 8.34 lb per gallon
Usual range for this trailer type: 10% to 15%
4. Hitch rating (from its label)
Class values use the top of each class in GSA's federal fleet guide, with 10% of it as tongue weight. Many receivers are rated differently, so the label on your hitch always wins.
🛻 Heaviest trailer you can tow with this load
Your 7,000 lb trailer fits every rating you entered, with 916 lb to spare on the tightest limit.
🚦 Every limit, checked
| Limit | Load | Rating | Used |
|---|---|---|---|
Payload (GVWR minus curb weight) Over 90% used | 1,490 | 1,600 | 93% |
Gross combination weight rating (GCWR) Within rating | 13,050 | 14,500 | 90% |
Manufacturer's maximum trailer rating Within rating | 7,000 | 9,000 | 78% |
Hitch rating: gross trailer weight Within rating | 7,000 | 10,000 | 70% |
Hitch rating: tongue weight Within rating | 840 | 1,000 | 84% |
Payload compares passengers, cargo and tongue weight with GVWR minus curb weight. GCWR compares the truck, everything in it and the whole trailer with the combined rating. Amber means more than 90% of a rating is used. Axle ratings (GAWR) need a scale, so they are not checked here.
📏 Maximum trailer by each limit
The lowest line is your real towing capacity for this load. Payload and hitch-tongue limits assume the same 12% tongue weight on a heavier trailer.
⚖️ Tongue weight check
📋 Step-by-step
- 1. Payload capacity. GVWR minus curb weight: 7,000 − 5,400 = 1,600 lb.
- 2. Tongue weight. 7,000 × 12% = 840 lb.
- 3. Payload used. Passengers and cargo plus hitch weight: 650 + 840 = 1,490 lb, leaving 110 lb.
- 4. Combined weight. Truck, load and whole trailer: 5,400 + 650 + 7,000 = 13,050 lb, against a GCWR of 14,500 lb (margin 1,450 lb).
- 5. Each limit as a trailer weight. By GCWR: 14,500 − 6,050 = 8,450 lb. By payload: (1,600 − 650) ÷ 12% = 7,916 lb. Trailer and hitch ratings are compared as entered.
- 6. Take the lowest. 7,916 lb, set by payload.
Towing capacity calculator: how much can you really tow?
An advertised towing number belongs to one lightly loaded truck. With family in the cab and gear in the bed, the question is which rating you hit first. This towing capacity calculator runs every check and names the tight one.
The five numbers that decide how much you can tow
NHTSA's towing guide explains that manufacturers' ratings cover tongue weight as well as the individual, combined and fully loaded weights at which a vehicle can safely tow. In practice that means five numbers:
- GVWR, the most the loaded truck may weigh, printed with the axle ratings (GAWR) on the certification label at the driver's door.
- Curb weight, the empty truck with fluids. GVWR minus curb weight is payload; the tire and loading placard states the most occupants and cargo may weigh.
- GCWR, the most truck and loaded trailer may weigh together, from the owner's manual or towing guide.
- Maximum trailer rating, which NHTSA notes can change with equipment such as the transmission or four-wheel drive.
- Hitch rating for trailer and tongue weight, stamped on the receiver or fifth-wheel hitch.
The towing capacity formulas
Each rating turns into a maximum trailer weight with subtraction and one division:
Payload capacity = GVWR − curb weight Tongue weight = trailer weight × tongue % Payload left = payload capacity − passengers − cargo − tongue weight GCW = curb weight + passengers + cargo + trailer weight Max trailer by GCWR = GCWR − (curb weight + passengers + cargo) Max trailer by payload = (payload capacity − passengers − cargo) ÷ tongue % Towing capacity = the lowest of all limits The whole trailer counts toward GCW, but only its tongue weight counts toward payload. That is why a heavy tongue can exhaust payload long before GCWR is reached.
Worked example 1: half-ton pickup and a 7,000 lb travel trailer
A pickup has a 7,000 lb GVWR, a scale-ticket curb weight of 5,400 lb, a 14,500 lb GCWR and a 9,000 lb towing rating. Two adults weigh 350 lb and the bed holds 300 lb of gear and hitch hardware. The trailer weighs 6,000 lb empty plus 1,000 lb of water and gear, with 12% on the tongue, and the receiver is rated 10,000 lb and 1,000 lb of tongue weight.
- Payload capacity: 7,000 − 5,400 = 1,600 lb. Tongue weight: 7,000 × 12% = 840 lb.
- Payload used: 350 + 300 + 840 = 1,490 lb, which leaves 110 lb, or 93% of payload in use.
- Combined weight: 5,400 + 650 + 7,000 = 13,050 lb against 14,500 lb, a margin of 1,450 lb.
- Maximum trailer by GCWR: 14,500 − 6,050 = 8,450 lb. By payload: 950 ÷ 12% = 7,916 lb. By the hitch tongue rating: 1,000 ÷ 12% = 8,333 lb.
The trailer fits, but the towing capacity for this load is 7,916 lb, set by payload, not 9,000 lb. One more 160 lb passenger would put the truck over its GVWR while GCWR still looked comfortable.
Worked example 2: three-quarter-ton truck and an 11,000 lb fifth wheel
A heavier truck has a 10,000 lb GVWR, a 7,200 lb curb weight, a 22,000 lb GCWR and a 14,000 lb fifth-wheel rating. It carries 400 lb of people and 350 lb of cargo, including the hitch. The loaded fifth wheel weighs 11,000 lb with 20% on the pin.
- Payload capacity: 10,000 − 7,200 = 2,800 lb. Pin weight: 11,000 × 20% = 2,200 lb.
- Payload used: 400 + 350 + 2,200 = 2,950 lb, 150 lb over (105%), so the truck would weigh 10,150 lb.
- Combined weight: 7,200 + 750 + 11,000 = 18,950 lb, 86% of GCWR, and the trailer uses 79% of its rating.
- Maximum trailer by payload: (2,800 − 750) ÷ 20% = 10,250 lb.
Every headline rating looks fine, yet the rig is overloaded, because a fifth wheel puts a large share of its weight in the bed: 20% here, and about 25% in GSA's fleet guide. A 10,000 lb trailer brings payload back to 2,750 lb of 2,800 lb.
Tongue weight, pin weight and how much trailer your payload allows
NHTSA describes tongue weight as the trailer weight pressing down on the hitch: too little can make the trailer sway, too much takes weight off the front wheels and dulls the steering. The U.S. Fish and Wildlife Service fleet policy says about 10% to 15% should rest on the hitch. GSA's fleet towing guide uses that range above 2,000 lb, caps lighter trailers at 200 lb and puts fifth wheels at about 25%. To measure it, set only the tongue, coupler at hitch-ball height, on a scale.
| Loaded trailer | 10% | 12% | 15% | 20% | 25% |
|---|---|---|---|---|---|
| 2,000 lb | 200 | 240 | 300 | 400 | 500 |
| 3,500 lb | 350 | 420 | 525 | 700 | 875 |
| 5,000 lb | 500 | 600 | 750 | 1,000 | 1,250 |
| 7,000 lb | 700 | 840 | 1,050 | 1,400 | 1,750 |
| 10,000 lb | 1,000 | 1,200 | 1,500 | 2,000 | 2,500 |
| 12,000 lb | 1,200 | 1,440 | 1,800 | 2,400 | 3,000 |
| 16,000 lb | 1,600 | 1,920 | 2,400 | 3,200 | 4,000 |
Turned around, the same arithmetic shows the heaviest trailer that the payload left after passengers and cargo can support, rounded down to the pound:
| Payload left for the hitch | 10% | 12% | 15% | 20% | 25% |
|---|---|---|---|---|---|
| 500 lb | 5,000 | 4,166 | 3,333 | 2,500 | 2,000 |
| 750 lb | 7,500 | 6,250 | 5,000 | 3,750 | 3,000 |
| 1,000 lb | 10,000 | 8,333 | 6,666 | 5,000 | 4,000 |
| 1,250 lb | 12,500 | 10,416 | 8,333 | 6,250 | 5,000 |
| 1,500 lb | 15,000 | 12,500 | 10,000 | 7,500 | 6,000 |
| 2,000 lb | 20,000 | 16,666 | 13,333 | 10,000 | 8,000 |
| 2,500 lb | 25,000 | 20,833 | 16,666 | 12,500 | 10,000 |
Large figures only mean payload is not the binding limit.
Hitch classes and what their ratings mean
NHTSA notes that the industry classifies hitches by the tongue and total weight they handle. GSA's fleet guide gives the limits below; the tongue column applies 10% to each limit as a planning figure, not a rating.
| Class | Trailer weight (GSA) | Tongue at 10% | Notes |
|---|---|---|---|
| I | up to 2,000 lb | 200 lb | Light duty; weight-carrying unless the vehicle maker says otherwise |
| II | 2,001 to 3,500 lb | 350 lb | Weight-carrying unless the vehicle maker says otherwise |
| III | 3,501 to 5,000 lb | 500 lb | Weight-carrying unless the vehicle maker says otherwise |
| IV | 5,001 to 12,000 lb | 1,200 lb | Weight-distributing anti-sway hitch required; over 10,000 lb may need a fifth wheel |
| V | set by the hitch maker | per label | Heavy-duty receivers rated by their maker; not defined in the GSA guide |
The weakest link sets the limit: receiver, ball mount, ball, coupler or vehicle. A 10,000 lb receiver on a truck rated for 6,000 lb is a 6,000 lb setup.
Advertised towing capacity, GCWR and SAE J2807
SAE J2807, first issued in 2008 and reaffirmed in November 2024, sets minimum performance criteria a tow vehicle must meet at its GCWR and a method for calculating its trailer weight rating, for vehicles up to 14,000 lb GVWR. For owners, the point is that the published rating is worked out for a defined, lightly loaded truck. Everything you add beyond that, from passengers to a bed cap, comes out of what you can tow.
How to use this calculator, and who it is for
- Pick the trailer type; fifth wheels switch the tongue default to 20%.
- Copy GVWR from the door label and GCWR and the trailer rating for your exact configuration from the towing guide. Use a scale weight for curb weight if you can.
- Enter the real weight of everyone and everything in the truck, hitch hardware included.
- Enter the trailer's empty weight plus its load, then the tongue percentage or a measured tongue weight.
- Add the hitch label ratings or tap a class preset; leave them blank to skip that check.
It suits first-time travel trailer buyers, boat owners, contractors with equipment trailers, horse owners with goosenecks and fleet managers who need a documented check of the truck they actually own.
Key terms
- GVWR: the maximum loaded weight of the truck, tongue weight included.
- GCWR: the maximum weight of truck and loaded trailer together.
- GAWR: the maximum load on one axle, listed front and rear.
- Curb weight: the truck with fluids but without people or cargo.
- Payload: GVWR minus curb weight, shared by occupants, cargo and tongue weight.
- GVW and GCW: actual scale weights of the loaded truck and the whole rig.
- Tongue or pin weight: trailer weight resting on a ball hitch, or on a fifth-wheel or gooseneck hitch.
- Dry weight: a trailer's empty weight before water, propane, batteries and gear.
What changes your towing capacity
- Configuration. Cab, engine, axle ratio and four-wheel drive change curb weight and ratings, so two trucks with the same badge can differ by thousands of pounds.
- People and cargo. Each pound in the truck lowers the GCWR limit by a pound and, at 12% tongue weight, the payload limit by more than eight.
- Accessories. Bed caps, toolboxes, bigger tires and the hitch itself all count as cargo.
- Trailer loading. Weight moved forward raises tongue weight; GSA suggests about 60% of the cargo in the front half and 40% in the rear.
Tips for towing within your limits
- Weigh the loaded rig at a public scale, as NHTSA advises, and redo the math with real numbers.
- Keep the trailer level, balance the load and secure it so it cannot shift.
- Cross the safety chains under the tongue, check the lights and set tire pressures for the load.
- Allow considerably more distance for stopping, in NHTSA's words; the Stopping Distance Calculator shows how fast it grows with speed.
- Drive at moderate speeds, since NHTSA notes sway grows more likely with speed. Do not fight sway with the truck's brakes; ease off and apply the trailer brakes by hand.
Limitations of this estimate
The calculator checks totals, not how weight is spread. It cannot see an overloaded rear axle, tires past their load rating or the effect of a weight-distribution hitch; only a scale can. If the placard's occupant-and-cargo figure is lower than GVWR minus curb weight, use the placard number. Brake, mirror and permit rules vary by state. GSA's fleet guide adds that the truck's brakes are certified for its GVWR, not its GCWR, so a heavy trailer needs brakes of its own.
Related calculators
- Stopping room for a loaded rig: Stopping Distance Calculator.
- Trip fuel and towing mileage: Fuel Cost Calculator and Gas Mileage Calculator.
- Bigger tires or a new axle ratio: Tire Size Calculator and Gear Ratio Calculator.
- Financing the trailer or boat: RV Loan Calculator or Boat Loan Calculator.
- Pounds and kilograms from a trailer spec: Unit Converter.
Sources
- National Highway Traffic Safety Administration, Towing a Trailer: Being Equipped for Safety, DOT HS 809 433 (April 2002, archived copy): ratings, tongue weight, hitches, brakes and driving tips.
- eCFR, 49 CFR 567.4: GVWR and GAWR on the certification label.
- eCFR, 49 CFR 571.110 (FMVSS No. 110): tire and loading placard.
- eCFR, 49 CFR 575.6: owner's manual load-limit steps.
- U.S. General Services Administration, Federal Supply Service, How 2 Select Tow Vehicles (2001, archived copy): tongue weight, hitch classes, loading and brakes.
- U.S. Fish and Wildlife Service, Service Manual 243 FW 5, Towing, Carrying Cargo, and Load Securement (2016): 10% to 15% tongue weight.
- SAE International, J2807 Performance Requirements for Determining Tow-Vehicle GCWR and Trailer Weight Rating (reaffirmed November 2024).
- U.S. Geological Survey, Water Science School: water at 8.34 lb per gallon.
⚠️ Common mistakes & edge cases
Treating the advertised maximum as your number
The headline rating belongs to one lightly loaded configuration. In the first example, a truck rated for 9,000 lb can tow only 7,916 lb with two adults and 300 lb of gear aboard.
Forgetting that tongue weight is payload
An 840 lb tongue uses as much payload as five 168 lb passengers. Leave the 2,200 lb pin weight out of the second example and a truck 150 lb over its GVWR seems to have 2,050 lb to spare.
Planning with the trailer's dry weight
Dry weight leaves out water, propane, batteries and gear. A 6,000 lb trailer carrying 1,000 lb of supplies is a 7,000 lb trailer on the road, with a heavier tongue.
Using a brochure curb weight
Options, a full tank, running boards and a bed liner add weight the base figure leaves out. A scale ticket for your own truck makes payload math trustworthy.
Assuming the hitch class sets the limit
A Class IV receiver says what the receiver can take, not the truck. The lowest rating among truck, receiver, ball mount, ball and coupler applies.
Mixing up conventional and fifth-wheel ratings
Ball-hitch and fifth-wheel ratings are often published separately, and pin weight runs well above tongue weight. Use the pair that matches your hitch.
❓ Frequently asked questions
How do I calculate my truck's towing capacity?
Subtract the loaded truck (curb weight plus passengers plus cargo) from the GCWR in the owner's manual. That is the heaviest trailer the combined rating allows. Then check payload: divide the payload left after people and cargo by the tongue percentage. Your towing capacity is the lowest of those two results, the manufacturer's trailer rating and the hitch rating.
How much can I tow with my truck?
As much as its tightest limit allows for the load you carry that day. A truck with a 7,000 lb GVWR, a 5,400 lb curb weight and a 14,500 lb GCWR carrying 650 lb of people and gear could tow 8,450 lb by GCWR and 9,000 lb by its rating, but at 12% tongue weight its remaining 950 lb of payload supports only 7,916 lb.
What is the difference between GVWR and GCWR?
GVWR is the most the truck itself may weigh, including passengers, cargo and tongue weight, and it is on the certification label at the driver's door. GCWR is the most truck and trailer may weigh together, including passengers, equipment and fuel. A trailer can pass the GCWR check and still push the truck over its GVWR.
How do I calculate payload capacity?
Subtract the curb weight from the GVWR, or read the tire and loading placard, which states the most that occupants and cargo may weigh together. Federal rules make owner's manuals show the next step: a 1,400 lb rating with five 150 lb passengers leaves 650 lb for cargo. When you tow, the tongue weight comes out of that 650 lb.
Does tongue weight count against payload?
Yes. The tongue or pin weight presses on the hitch, so the truck carries it like cargo in the bed. The owner's manual statement required by 49 CFR 575.6 says that load from a trailer is transferred to your vehicle and reduces the cargo capacity left. Count the hitch hardware too, such as a weight-distribution head or a fifth-wheel hitch.
How much tongue weight should a trailer have?
Plan on 10% to 15% of the loaded weight for a conventional trailer, the range in the U.S. Fish and Wildlife Service fleet policy. GSA's fleet towing guide caps trailers up to 2,000 lb at 200 lb and puts fifth-wheel trailers at about 25%; the calculator treats 15% to 25% as the planning range for pin weight. Too little invites sway, too much unloads the front wheels.
What do trailer hitch classes mean?
They group receivers by the trailer and tongue weight they are built for. GSA's federal fleet guide lists Class I up to 2,000 lb, Class II up to 3,500 lb, Class III up to 5,000 lb and Class IV up to 12,000 lb with a weight-distributing hitch. Many current receivers carry other numbers, so your hitch label counts, and the vehicle rating can be lower still.
What is SAE J2807 and does my truck's rating use it?
SAE J2807 is an SAE International recommended practice that sets minimum performance criteria for a tow vehicle at its GCWR and a standard method for calculating its trailer weight rating. It covers vehicles up to 14,000 lb GVWR, was first issued in 2008 and was reaffirmed in November 2024. Your model year's towing guide says whether its ratings follow it.
How do I find out how much my trailer weighs?
A trailer's label or brochure weight is usually its dry weight, before batteries, propane, water and gear. NHTSA advises a realistic loaded estimate and says the best way to know the actual weight is a public scale. Water alone adds about 8.34 lb per gallon, so a full 40-gallon fresh tank adds about 334 lb.
Do I need brakes on my trailer?
Above a certain weight, usually, and each state sets the threshold. NHTSA's towing guide notes that many states require a separate braking system and a breakaway switch on trailers with a loaded weight over 1,500 pounds, and some require brakes on every axle. The truck's own brakes are rated for its GVWR, not for the whole combination.
💡 Good to know
Every 100 lb in the cab costs about 833 lb of trailer
At 12% tongue weight, each 100 lb of passengers or cargo lowers the payload-limited trailer by 100 ÷ 12% = 833 lb but the GCWR-limited trailer by only 100 lb. In the first example, adding 350 lb to the 650 lb aboard drops the payload limit from 7,916 lb to 5,000 lb.
The door opening holds the official numbers
Federal rules put GVWR and the axle ratings on the certification label at the driver's door and the occupant-and-cargo limit on the tire placard. GCWR and trailer ratings are in the owner's manual or towing guide.
A weight-distribution hitch spreads weight, it does not add capacity
NHTSA notes that a weight-distributing hitch can move weight back to the front axle when a heavy tongue lightens the steering. The rig sits and steers better, but no rating on the labels changes.