There’s 2 ways you can choose to do that
The simpler way to do this would be to just eat the meal to hunger- like eat till you feel satiated and stop – so in this case it’s not a specific serving size you are going off of, but letting your body tell you when you are full- I know that might sound a bit scary but actually with the way the meals are designed with lots of fiber and veggies, most people actually get full before finish a full serving of the p3tolife meal- I get this all the time- so your satiation level often ends up being a very reliable guide of how much of the meal to it and the bonus is that this is the least work to figure out.
The 2nd option would be to actually measure the volume of the full meal then divide that by number of servings –
ie if the meal makes a total of 8 cups of food, and it makes 4 servings, you would eat 2 cups for your serving- does that help? I know that would be more time consuming and likely some of your dishes will be larger volume which I know can be hard to measure- you can either use a 4 cup measuring glass or there are these larger measuring pitchers of either 4 quarts (16 cups) or 2 quarts (8 cups).
There’s 4 cups in 1 quart. I hope that helps!