Calories in Sourdough Starter

I’d suggest you do some research via Google because there are way too many variants in an individual starter for any of us to guess at.

Type of flour(s) used, how old your starter is, how much and how often you feed/discard and use parts of it.

Quite honestly, as someone who uses a sourdough starter regularly I think it’s virtually impossible to even approach any form of accuracy for the starter itself.

If my life depended on figuring out a calorie count for a loaf made using a starter I’d calculate the other ingredients in the loaf and add the equivalent extra weight of the starter as if it were just the same volume of flour. I can think of no other way to do it!