What is egg-as-hydration?

A large egg is about 75% water by weight, so eggs in a dough contribute meaningfully to total hydration. A bread that lists 20% eggs and 50% water is actually closer to 65% total water (50 + 20×0.75 = 65). The calculator tracks ingredients separately, but understanding the math matters when comparing enriched recipes to lean ones, or when substituting eggs for milk.