You will need to use a scale that provides weight in grams or ounces.
To find the weight of a product that must be weighed in a container (for example, salad dressing), you will need to perform the following steps:
First, you will need to weigh the empty container that you will be using and record that weight.
Next, add your product to the container, and record the total weight of the container with your product inside.
Then, subtract the weight of the empty container (from step 1) from the weight of the container with the product inside (from step 2). This will give you the weight of the product itself, without the container.
For example: If the weight of the bowl or container in which you weight your food is 0.5 ounces, and the total weight of your food product plus the container is 4 oz., then the weight of your product itself will be 4 oz-0.5 oz=3.5 oz