How much valve oil is used for a trumpet per use?

Typically, one drop of valve oil is used per valve on a trumpet per use. This amount may vary depending on the preferences of the player and the type of trumpet being used. Some players may prefer to use a little more or less oil, and some trumpets may require more or less oil to function properly. It is important to use only a small amount of oil, as too much oil can cause the valves to stick and make it difficult to play the trumpet.