How much is 40 ml in teaspoons?

1 teaspoon (tsp) is equivalent to approximately 4.92892 milliliters (mL). Therefore, to convert 40 mL to teaspoons, we can divide the volume in milliliters by the volume of 1 teaspoon in milliliters:

$$40\text{ mL }/ 4.92892\text{ mL/tsp} \approx 8.1189\text{ tsp}$$

So, 40 mL is approximately equal to 8.12 teaspoons.