Trailer Sway Control Calculator

Trailer sway — that dangerous side-to-side fishtailing motion — is often caused by improper weight distribution, and the Trailer Sway Control Calculator tells you whether your setup is safe before you hit the road. Enter your gross trailer weight, tongue weight, and cargo weight, along with your rear axle to tow ball distance, tow ball to spring bar connection, and tow ball to trailer axle measurements. You'll get your tongue weight percentage, sway control status, weight distribution required, and recommended hitch capacity.

lbs

Total weight of trailer plus all cargo

lbs

Downward force on hitch ball

lbs

Weight of all items loaded in trailer

inches

Distance from rear axle centerline to hitch ball

inches

Distance from ball to spring bar attachment point

inches

Distance from hitch ball to center of trailer axles

Results

Tongue Weight Percentage

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Weight Distribution Required

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Sway Control Status

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Recommended Hitch Capacity

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Frequently Asked Questions

What is the ideal tongue weight percentage for safe towing?

The ideal tongue weight should be 10-15% of the gross trailer weight. This range provides optimal stability and control while preventing excessive stress on the tow vehicle's rear axle.

How does tongue weight affect vehicle stability?

Proper tongue weight keeps the trailer stable by maintaining downward pressure on the hitch. Too little tongue weight can cause dangerous trailer sway, while too much can overload the rear axle and reduce steering control.

When do I need a weight distribution hitch?

Weight distribution hitches are recommended when your trailer's gross weight exceeds 50% of your tow vehicle's weight, or when tongue weight exceeds the vehicle's tongue weight rating without weight distribution.

What causes trailer sway and how can I prevent it?

Trailer sway is caused by improper weight distribution, crosswinds, passing vehicles, or road conditions. Prevent it by maintaining proper tongue weight, using sway control devices, and loading cargo properly.

How do I measure tongue weight accurately?

Use a tongue weight scale or bathroom scale with a board. Place the trailer tongue on the scale with the trailer level. The reading should be 10-15% of your gross trailer weight.

Can I adjust tongue weight by moving cargo in my trailer?

Yes, moving cargo forward increases tongue weight, while moving it backward decreases it. However, ensure the trailer remains balanced and doesn't exceed axle weight limits.

What's the difference between gross trailer weight and cargo weight?

Gross trailer weight includes the empty trailer weight plus all cargo. Cargo weight is only the weight of items loaded into the trailer, not including the trailer's own weight.