You don’t need to use that 1g protein = 4 cal or anything like that to calculate calories. Just use the nutritional information on the packaging (and google the few things you don’t have packaging for).
If you’re curious, the rest of the weight is probably mostly water
You(and most people) will probably not count calories accuratly. But calorie counting works for weight loss/gain, cause even if you don’t properly count them, you can still lower/increase your perceived calories to make the weight Go down/up.
It’s almost always water. All food just like anything alive is mostly water.
This is why when counting calories it’s important to know if you should weigh the food before or after cooking, because cooking food takes significant water out and it’s always a variable amount.
I don’t understand people’s obsession with counting calories.
And I think it might be unhealthy.
Just eat a balanced diet, whole grains, fruits/veggies/legumes, nuts, some fish/meat but not too much. Listen to your body and don’t overeat.