The term "pinch" is an informal measurement used in cooking and baking to indicate a small, approximate amount of an ingredient. However, it's not an exact or standardized measurement. When a recipe calls for a pinch of salt, it typically means a small amount that can be held between your thumb and forefinger.
The actual amount can vary depending on the size of your fingers and how much salt you can hold. On average, a pinch of salt is considered to be approximately 1/16th to 1/8th of a teaspoon. Some chefs or cooks might use a three-finger pinch, while others may use just two fingers.
If you want to be more precise, you can use measuring spoons to get an accurate amount. For example, a dash of salt is about 1/16th of a teaspoon, and 1/8th of a teaspoon is a good approximation for a pinch of salt. However, in most cases, a pinch is used to add just a hint of salt for flavor, and exact measurements are not critical.