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Weighbridges used for trade 

Weighbridges determine the mass of a vehicle, including prime movers and connected trailers.

You can use them to weigh goods such as farm produce, agricultural products, scrap metal and landscape materials weighing over 3 tonnes.

For trade, you can use weighbridges to:

  • buy or sell goods
  • determine freight costs or other charges based on weight
  • determine a tax.

Public weighbridges

Public weighbridges are open for use by the public, usually for a charge.

Find a public weighbridge.

Weighing methods

A weighing may be:

  • direct – you should use this method where possible as it is the most accurate and weighs the entire vehicle in one weighing
  • end-and-end – if a vehicle does not fit on the platform, you can weigh the front and rear separately. In order to conduct end-and-end weighing the weighbridge must be approved by the National Measurement Institute (NMI) for this purpose. To find out how to apply, contact

You can also use a weighbridge to separately record the weight of axles (or groups of axles) to comply with local transport regulations.

Operating a weighbridge

If you own a weighbridge used for trade, you must ensure that:

  • the NMI has approved your type of weighbridge 
  • a servicing licensee has verified your weighbridge
  • you and your operators are correctly trained and conduct weighings in the correct manner
  • you keep the weighbridge clean and in good working order
  • a servicing licensee verifies them after each repair or adjustment.

You are responsible for making sure your weighbridge is correct at all times.

You should have your weighbridge tested regularly to make sure it weighs correctly.

Public weighbridges

To operate a public weighbridge, the person who makes a weighbridge available for public weighings must:

Weighbridge approaches

To meet operational requirements, you must ensure the approaches to your weighbridge:

  • have a hard, true and durable surface of concrete or another NMI-approved material
  • are in good condition and have not deteriorated
  • have a perimeter that is clearly indicated by painted marks or other NMI-approved means (if used for end-and-end or axle measurements)
  • are arranged so that drainage from the surface of the approach does not flow into the pit
  • are in the same plane as the platform for a minimum distance of either:
    • 3 metres, if the length of the platform is less than 18 metres
    • 1 metre, if the length of the platform is 18 metres or more.

Find out more by reading our:

Conducting weighings

While conducting weighing using a weighbridge, the operator must ensure that:

  • there is a continuous gap between the weighbridge platform and the edge of the weighbridge surround to prevent binding
  • there are no stones or other foreign matter jammed between the platform and its surrounds as this may cause binding
  • the weighbridge structure and surrounds are in good condition with no loose bolts or broken, missing or rusty components
  • there is no excess water on the weighbridge platform during weighing as water can accumulate and affect zero or balance 
  • there is no debris on the weighbridge prior to each weighing
  • loose loads—such as sand—are not accumulating in the pit or building up on the platform as it can affect zero or balance
  • there is no water or debris under the weighbridge platform
  • the indicator shows zero prior to use.