Tare weight is the weight of a vehicle or container when it is empty. This weight is used in calculations of net weight for tasks which range from properly charging customers for consumer goods to taxing laden trucks as they cross borders. To calculate the net weight of a load, the container is weighed to establish the tare weight, loaded and then weighed again for the gross weight; the tare is subtracted from the gross to find out how heavy the load is. This term can also be used in the culinary or food service industries, where it may refer to the weight of inedible parts of different foods.
Tare Weights in Transportation
Many vehicles have marking plates with information such as their tare weight. This is especially common with railway cars and trucks used in shipping, so that the net weight of the load can be easily calculated at any point without having to empty the vehicle to find out the tare weight. Such vehicles can be driven or pulled onto large and very sensitive scales for the purpose of weighing at borders and check-in stations.
In shipping, tare weight is extremely important, because it is used to determine the value of a load, and to calculate taxes. Truckers in many countries pay a set tax rate depending on how heavy their loads are, to ensure that trucking companies, which contribute to the degradation of the roadway, help to maintain it. Weights are also used to track loads, ensuring that no fraudulent activity occurs; this is especially important along borders where trade tariffs may be calculated. If a change in weight is noted from one stop to the next, then it may indicate that goods were unloaded illegally.
Smaller Scales and Consumer Use
Many scales have a “tare weight” setting, which allows the user to place an empty container on the scale and hit the tare button to zero the scale out. In some cases, regularly used weights can be saved in a scale. A store might want to save the setting for the glass jars it uses for olive oil, for example, so that oil sold by weight can be more quickly measured.
Cooking and Culinary Use
Many cooks use scales for recipes which call for ingredients by weight, rather than volume. Weight measurements are much more reliable than volume ones, which is why many baking recipes indicate ingredients by weight. Tare weight can also refer to the excess parts of food not used in cooking. A chef who needs five pounds of apples for a recipe, for example, needs to consider the weight of the core and seeds that are not used in making the dish. These components can be referred to as "tare" and are not part of the final weight needed in following a recipe.