The general rule of thumb is: 1 teaspoon of dried = 1 tablespoon of fresh
Many recipes in cookbooks call for the use of fresh spices. Often it is the wrong time of year for fresh spices, or you just don't have the particular spice available and do not want to run to the market to buy it. Your best solution is to substitute dried spices in place of the fresh. Dried spices are more potent than their fresh counterpart so you will need to use less of the dried product.
1. Determine whether the dry spice you are going to use for your recipe is powdered or crushed. This information can be found on the label and is important to make the conversion from fresh to dry.
2. Measure 1/3 teaspoon of powered spices for every 1 tablespoon of fresh spices called for in the recipe.
3. Measure 1/2 teaspoon of crushed spices to substitute for every 1 tablespoon of fresh.
4. Taste the recipe as it cooks. Add small amounts, i.e., 1/8 teaspoon, of the crushed or powdered spice if the dish needs the additional flavor.