Weight of 1 milliliter (ml) of pure water at temperature 4 °C = 1 gram (g). Thus 1 US teaspoon (tsp) = 4.92892159 grams (g) = 4.92892159 milliliters (ml) = 1/6 or 0.166666667 US fluid ounce (fl. oz.) = 1/3 US tablespoons (tbsp). The teaspoon is rounded to precisely 5 mL (0.169070114 US fluid ounces) by US federal regulations for food labeling purposes.