0.25 teaspoons of garlic powder is a small amount that measures 0.022 oz (616 mg). You can picture this quantity as being about the size of a blueberry.

In kitchen measures
0.25 teaspoons
0.25 tsp · 0.083 tbsp · 0.0052 cups
about the size of a blueberry
Garlic powder typically ranges 0.45–0.55 g/mL depending on how it's packed. A firmly packed scoop weighs more.