Common substitutions for evaporated milk include half-and-half, heavy cream or whole milk. When making these substitutions, use equal amounts. For example, if substituting 1/2 cup of evaporated milk, use a 1/2 cup of either whole milk, heavy cream or half-and-half.
Evaporated milk is a form of dehydrated milk, in which approximately 60 percent of the water in fresh milk has been extracted. This extraction process makes the milk more shelf stable, with the ability to be canned and used at a later date. Adding an equivalent amount of water to evaporated milk will make it resemble the consistency of fresh milk. Evaporated milk was especially popular before home refrigeration became more accessible and it still is a common ingredient in many desserts.