Servings per container is a declaration
On this page11
The panel structure
The subheading Serving Size goes under the heading Supplement Facts, and the subheading Servings Per Container goes under Serving Size. Both are required placements.
Which makes the container part of the label
Servings per container is the fill divided by the serving. Choose a different container and the declared number changes.
And the serving is not the maker's choice
This is the point most often got wrong. The regulation determines serving size by reference to 21 CFR 101.9(b) and the reference amounts in 101.12(b) Table 2, not by what the label recommends.
Which is the same table the edibles property is built on
The Reference Amounts Customarily Consumed, where candies are 30 grams and syrups are 30 millilitres. A supplement does not escape it by being a supplement.
So two numbers are fixed before the container is chosen
The reference amount, from the table, and the fill, from the container. Servings per container falls out of them.
And it is usually a round number people want
30 servings and 60 servings are the commercial shapes, which means the container is being chosen to produce a tidy declaration.
Which is a legitimate reason to pick a size
And it is worth knowing that the declaration follows the arithmetic rather than the marketing. A 60 count label on a 45 serving jar is a labeling problem.
For a gummy the unit is a piece
And the mass of a piece is a property of your recipe, not of the jar. Which is the same gap the edibles property names: our capacity field is in millilitres and the reference amount is in grams.
So weigh a filled jar
One measurement per recipe and per size. It gives the fill mass, and from that the piece count and the servings per container.
We do not publish a fill weight
Because it depends on the piece, and a published estimate would be laid out against. Our capacity is a nominal volume.