Spring scales are weighing scales usually measure force, that could be measured in units of force such as newtons or pounds-force. These scales typically cannot be used for any commercial applications unless their springs are temperature compensated or used at a quite constant temperature. They are scales which are legal for commerce and could be calibrated for the accurate measurement of mass (quantity measured for weight in commerce) in the position in which they are used. They could give an accurate measurement in terms of kilograms or pounds for this purpose.

Spring scales measures weight, the force of gravity on an object, and are typically calibrated in units of force. They have two sources of error that the balance scales do not have; the measured weight vary with the strength of the local gravitational force, as 0.5% at different locations and the elasticity of the measurement spring can vary a little with temperature. These scales that are legal for commerce will either have temperature compensated springs or are used at a constant temperature, and should be calibrated at the site in which they are used, to eradicate the effect of gravity variations.