What is my tow ball weight?

Your tow ball weight, also known as tongue weight, is the vertical force the trailer applies to your hitch. It’s typically about 9–15% of the trailer’s gross weight, with 10% being a common starting point. Getting this figure right is crucial for stability, braking performance, and overall towing safety.

What tow ball weight means

Tow ball weight is the downward force that the trailer’s coupling transfers to the hitch ball. It reflects how the trailer’s load is distributed over the tow vehicle’s rear axle and, in turn, how the entire towing setup behaves on the road. Correct tongue weight helps prevent trailer sway, improves braking response, and protects the vehicle’s rear suspension and payload capacity.

Key concepts to know

Tongue weight is expressed as a percentage of the gross trailer weight (GTW). Most manufacturers and towing professionals recommend keeping this percentage within a safe range to balance weight between the tow vehicle and the trailer. For many setups, 9–15% of GTW is considered acceptable, with a common target near 10–12%.

Estimating your tow ball weight

There are practical ways to estimate TBW when you don’t have professional weighing equipment handy. The following methods provide starting points you can use to assess load balance before you test-drive with your trailer.

• Quick estimation based on trailer weight: If you know the trailer’s GTW, multiply by about 0.10 (10%) to estimate tongue weight. This gives you a reasonable starting point, which you should verify in real driving conditions.


• Use typical ranges as a guideline: In most everyday caravans and light trailers, tongue weight will fall roughly in the 9–15% of GTW range. Use this as a benchmark when loading items.


• Check manufacturer specs: Some trailers publish a tongue weight or a tongue weight ratio in their documentation. Use these figures for a more precise target.

Starting from a 10% target is common practice, but individual setups vary. After loading the trailer, you should verify and adjust based on actual handling and sway behavior.

Measuring tongue weight precisely

For accurate TBW, professional measurement or dedicated tools are recommended. The following options provide reliable results and are widely used by tow enthusiasts and service centers.

• Dedicated tongue weight scale: A portable scale that sits under the hitch ball can give an immediate readout of tongue weight. This is the easiest and most direct method for many tow setups.


• Weigh stations or trailer service facilities: Many scales can measure tongue weight when the trailer is hitched. Staff can help you obtain the exact figure and confirm you’re within the recommended range.


• Vehicle and trailer on a weighbridge method (professional): Some shops will weigh the entire vehicle–trailer combination to determine tongue weight indirectly, then provide guidance on load adjustments. This is less common for casual users but highly accurate.

Precise measurement helps ensure your load is balanced correctly and that you stay within the vehicle’s and trailer’s rated specifications, including the gross combination weight rating (GCWR) and gross trailer weight (GTW).

Adjusting tongue weight for safety and stability

If your initial measurements show TBW outside the recommended range, you can rebalance the load by redistributing cargo within the trailer or adjusting how you load the towing vehicle. The following steps outline practical load-balancing adjustments.

• Move cargo forward or backward on the trailer: If TBW is too high, shift heavier items toward the front of the trailer; if TBW is too low, move some weight toward the rear only within safe limits.


• Repack for even weight distribution: Place lighter items higher up and toward the center, keeping heavy items low and close to the coupling to improve stability.


• Test after each adjustment: Re-measure tongue weight with your scale or at a weighing facility to confirm you’re within the target range.


• Consider a weight distribution hitch (WDH) if you frequently tow heavier trailers: A properly set up WDH helps distribute tongue weight more evenly across the tow vehicle’s axles. Follow the manufacturer’s setup instructions carefully.

Effective load distribution not only improves handling and braking but also reduces wear on the hitch and tires. Always confirm that the final tongue weight adheres to both the trailer manufacturer’s specs and your vehicle’s GCWR.

When to seek professional help

If you’re unsure about how to measure tongue weight or how to interpret the results, consult a qualified trailer or towing professional. They can help you select the right scale, perform accurate measurements, and advise on optimal load distribution for your specific vehicle and trailer combination.

Summary

Tongue weight is the vertical force the trailer places on the hitch ball and is commonly around 9–15% of GTW, with 10% as a practical starting point. To determine your TBW, you can estimate using GTW and percentage targets, or obtain a precise measurement with a tongue weight scale or a weigh station. If tongue weight falls outside recommended ranges, redistribute load and re-check. For frequent heavy-tow setups, a properly adjusted weight distribution hitch can improve stability, but always follow manufacturer guidance and consider professional advice when in doubt.

What determines towball weight?

Tow ball weight, also referred to as tow ball mass, is the weight pushing down on the tow ball by the coupling of the RV being towed. Maximum tow ball weight is specified by both the vehicle and trailer manufacturer. Typically, it is 10% of the Aggregate Trailer Mass (ATM). You must use the lesser of the two limits.

How do I find out my towball weight?

There are many ways to measure tow ball weights. You could take your caravan to professional weighbridges or use a set of bathroom scales. You might buy a specialist set of tow ball weight scales for accurate calculations.

How do I find out my towing weight?

Many drivers ask, “How much can my car tow?”—but the answer depends on your individual vehicle, not just its make or model. The only reliable way to check is by reading the Vehicle Identification Number (VIN) Plate, which shows the precise towing limit set by the manufacturer for your specific vehicle.

How do I know what my hitch weight is?

To calculate hitch weight, you can either use a two-scale method or a single-scale method. With a two-scale method, you weigh the tow vehicle and loaded trailer together, then weigh the tow vehicle alone, and subtract the second weight from the first. With a single-scale method, you drive the tow vehicle onto the scale first without the trailer, then connect the trailer and weigh the tow vehicle and trailer together without having the trailer wheels on the scale. The difference is the tongue weight. 
Two-scale method

1. Weigh the tow vehicle and loaded trailer: Drive both the tow vehicle and the trailer onto a commercial or platform scale at the same time and record the combined weight. 
2. Weigh the tow vehicle alone: Unhitch the trailer and weigh only the tow vehicle, recording this "solo" weight. 
3. Calculate the hitch weight: Subtract the "solo" weight from the combined weight. The result is the hitch weight (also known as tongue weight). 
   • Formula: Hitch Weight = (Combined Weight) - (Tow Vehicle Solo Weight) 

This video explains how to measure tongue weight using a bathroom scale: 29sWandering WagnersYouTube · Jul 7, 2016
Single-scale method

1. Weigh the tow vehicle alone: Drive the tow vehicle onto the scale and record its weight. 
2. Weigh the tow vehicle with the trailer: Connect the trailer, but ensure the trailer's wheels do not touch the scale. Weigh the tow vehicle and trailer together and record this weight. 
3. Calculate the hitch weight: Subtract the weight of the tow vehicle from the combined weight of the tow vehicle and trailer. The difference is the hitch weight. 
   • Formula: Hitch Weight = (Tow Vehicle + Trailer Weight) - (Tow Vehicle Weight) 

Using a bathroom scale (for bumper-pull trailers) 

1. Place a bathroom scale under the trailer's jack.
2. Slowly lower the jack until the trailer is resting solely on the scale and the coupler is no longer touching the hitch ball.
3. Multiply the number on the scale by 3 to get the estimated tongue weight.
   • Formula: Tongue Weight = (Bathroom Scale Reading) x 3