ISO 7451:2007 specifies a method for estimating the volume of materials which a hoe-type or grab-type bucket of a hydraulic excavator or backhoe loader can normally contain. The volume assessments are based on the internal dimensions of the bucket and on the representative volumes at the top of the bucket.
The method employs the technique of dividing the complex shape of the material in the bucket into simple geometric shapes.
This method of assessment is intended to provide a conventional means of comparing bucket capacities. It is not intended to be used to define true capacities.