acalculator

What should my tongue weight be?

Type the loaded weight of your trailer and the range your manual gives. The tongue weight calculator shows the tongue weight to aim for, and, if you weighed the tongue, what share of the trailer weight it is.

Your numbers

Units
Lowest tongue weight, lb
500

Aim for a tongue weight of 500 to 750 lb.

Highest tongue weight, lb
750
Lowest tongue weight, kg
226.8
Highest tongue weight, kg
340.2

Lowest tongue weight, lb: 500. Aim for a tongue weight of 500 to 750 lb.

How to calculate

Computes the tongue weight range for a trailer, 10 to 15% of the loaded trailer weight by default or the range in your manual, and the percentage a measured tongue weight is.

Example with the default inputs (Loaded trailer weight 5,000 lb, Lowest share 10%, Highest share 15%): Aim for a tongue weight of 500 to 750 lb.

Method: tongue weight range = loaded trailer weight × lowest share ÷ 100 to loaded trailer weight × highest share ÷ 100; measured share = tongue weight ÷ loaded trailer weight × 100.

  • The trailer is a conventional (bumper-pull) trailer on a ball hitch; fifth-wheel and gooseneck trailers carry a larger share.
  • The default range is 10% to 15%, the common US guidance for a conventional trailer (Hyundai’s manual); too little tongue weight makes a trailer sway. Kia’s US manual caps it at 10% and NSW Government gives about 5 to 10%. Set the range and the maximum tongue load your own manual gives.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Loaded trailer weight 5,000 lb, Lowest share 10%, Highest share 15% gives Lowest tongue weight, lb 500, Highest tongue weight, lb 750, Lowest tongue weight, kg 226.796185, Highest tongue weight, kg 340.194278.Source: 1 lb = 0.45359237 kg (NIST SP 811); Hyundai owner’s manual, If You Decide to Pull a Trailer: the tongue load measured at the hitch when fully loaded should be within 10–15% of the total weight of the trailer, https://ownersmanual.hyundai.com/full_webhelp/LX3/2026/en_US/topic_snf_hxj_x5b.html (retrieved 2026-10-18)
  2. Loaded trailer weight 3,500 lb, Lowest share 10%, Highest share 15%, Measured tongue weight 300 lb gives Lowest tongue weight, lb 350, Highest tongue weight, lb 525, Measured share 8.571429, Measured tongue weight is below the range.Source: Hyundai owner’s manual, If You Decide to Pull a Trailer: the tongue load measured at the hitch when fully loaded should be within 10–15% of the total weight of the trailer, https://ownersmanual.hyundai.com/full_webhelp/LX3/2026/en_US/topic_snf_hxj_x5b.html (retrieved 2026-10-18)
  3. Loaded trailer weight 4,409 lb, Lowest share 10%, Highest share 15%, Measured tongue weight 551.2 lb gives Lowest tongue weight, kg 200, Highest tongue weight, kg 300, Measured share 12.5, Measured tongue weight is within the range.Source: Hyundai owner’s manual, If You Decide to Pull a Trailer: the tongue load measured at the hitch when fully loaded should be within 10–15% of the total weight of the trailer, https://ownersmanual.hyundai.com/full_webhelp/LX3/2026/en_US/topic_snf_hxj_x5b.html (retrieved 2026-10-18); Kia owner’s manual (KA4, 2024, US), If you do decide to pull a trailer: tongue weight at most 10% of the loaded trailer weight, https://ownersmanual.kia.com/full_webhelp/KA4/2024/en_US/topics/t00397.html (retrieved 2026-10-18); NSW Government, Towing a trailer or caravan: as a general rule, the vehicle should carry about 5 to 10% of the loaded trailer’s mass at the coupling, https://www.nsw.gov.au/driving-boating-and-transport/roads-safety-and-rules/vehicle-safety-and-compliance/towing-a-caravan (retrieved 2026-10-18)

How it works

  • Lowest tongue weight = loaded trailer weight × lowest share ÷ 100
  • Highest tongue weight = loaded trailer weight × highest share ÷ 100
  • Measured share (only when you type a measured tongue weight) = measured tongue weight ÷ loaded trailer weight × 100
  • The measured tongue weight is below the range when its share is under the lowest share, above the range when it is over the highest share, and within the range otherwise (a share exactly at either end is within).

The lowest share is 10% and the highest 15% by default: the common US guidance for a conventional trailer, as Hyundai's manual gives it. Too little tongue weight makes a trailer sway, so the default does not go lower. Other sources differ: Kia's US manual caps tongue weight at 10% for its vehicles, and NSW Government in Australia gives about 5 to 10%. Type the range your own manual gives. Results show in pounds and in kilograms (1 lb = 0.45359237 kg exactly).

Exact arithmetic. Each weight and percent is read as the exact decimal you typed, in its unit, so every result is exact.

Rounding. Pounds show as whole numbers, kilograms and the measured share with at most 1 decimal, each rounded half up, trailing zeros left off.

When there is no answer. If the lowest share is more than the highest, the page gives no answer.

Assumptions

  • The trailer is a conventional trailer on a ball hitch.
  • The loaded trailer weight is the trailer plus its full load.
  • Weights are at least 1 kg and at most 100,000 kg; shares are more than 0% and at most 100%.

Worked examples by hand

A 5,000 lb loaded trailer. 5,000 × 10 ÷ 100 = 500 lb (226.8 kg) to 5,000 × 15 ÷ 100 = 750 lb (340.2 kg).

A 3,500 lb trailer with a 300 lb tongue. The range is 350 to 525 lb. 300 ÷ 3,500 × 100 = 8.6%, which is below the range.

A 2,000 kg trailer with a 250 kg tongue. The range is 200 to 300 kg. 250 ÷ 2,000 × 100 = 12.5%, within the range. With NSW Government's 5 to 10%, or Kia's 10% maximum, the same tongue is too heavy.

Other questions people ask

How do I calculate tongue weight?

Multiply the loaded trailer weight by 10% and by 15%, the common US range for a conventional trailer. For a 5,000 lb trailer, the tongue weight should be between 5,000 × 0.10 = 500 lb and 5,000 × 0.15 = 750 lb. If your manual gives other shares, use those.

How do I work out my tongue weight percentage?

Divide the measured tongue weight by the loaded trailer weight and multiply by 100. A 300 lb tongue on a 3,500 lb trailer is 300 ÷ 3,500 × 100 = 8.6%, which is below 10%.

What happens if the tongue weight is too light?

Too little weight on the hitch makes the trailer more likely to sway. Move load forward of the trailer axle, then weigh the tongue again.

What happens if the tongue weight is too heavy?

Too much weight on the hitch overloads the rear axle of the tow vehicle and takes weight off the front wheels, which can hurt steering and braking. Move load back toward the axle, and never go over the vehicle’s maximum tongue load or GVWR.

How do I measure tongue weight?

Use a tongue weight scale under the coupler. Or use a public vehicle scale: weigh the tow vehicle alone, then again with the loaded trailer hitched but its wheels off the scale. The gain in the vehicle’s total weight is the tongue weight. Weigh it loaded as you will travel.

Does every vehicle use 10 to 15%?

No. Kia’s US manual caps tongue weight at 10% for its vehicles, and NSW Government in Australia gives about 5 to 10%. Fifth-wheel and gooseneck trailers carry a larger share. Change the lowest and highest share to match your manual.