Pure cranberries have an extremely tart flavour, as you may know if you have ever eaten one or had a sip of pure, unsweetened cranberry juice. To achieve the sweet yet mildly sour flavour familiar in most preparations -- like the cranberry sauce at Thanksgiving dinner -- you must add a significant amount of sugar to the cranberries. Most dried cranberries already have this sugar added, making a substitution with fresh cranberries slightly more complicated.
Measure out one cup of whole, fresh cranberries for each ¾ cup of dried cranberries. For example, if the recipe calls for half a cup of dried cranberries, measure out 2/3 cup of fresh cranberries. Dried cranberries are naturally more concentrated than fresh cranberries because most of the water in them has been removed.
Add 1/8 cup sugar to the recipe for each cup of fresh cranberries you are using. This is to replace the sugar that would otherwise come from the dried cranberries.
Reduce the amount of water in the recipe by ¼ cup per cup of fresh cranberries you are using to make up for the extra liquid that the fresh cranberries will add.
Make the recipe as normal, adding the fresh cranberries at the same time as you would have added the dried cranberries. There is an exception to this rule: if you would have added the dried cranberries at the end of the cooking process, add the fresh cranberries much sooner. This will give them time to cook and blend in with the recipe.