A sprig, as defined above, will yield about 1/3 teaspoon of fresh leaves (loosely packed). Dried thyme and fresh thyme are interchangeable with some difference in flavor. The standard ratio is 3 t fresh = 1 t dry, but this is often hard to measure. Figure 1/4 teaspoon of dried thyme leaf is equivalent to a fairly large sprig, such as the lower one in the photo above. If you use powdered thyme, use 3/4 as much as you would dried leaf. Keep in mind that cookbook writers are often sloppy and often presume their methods and sizes mean the same thing the world around.