5 grams of matcha powder is 0.176 oz (5 g) in weight and 0.966 tbsp (14.3 mL) in volume. When poured into a loose pile, it is 1.95 in (4.95 cm) wide and 0.877 in (2.23 cm) tall, which is about the size of a grape.

In kitchen measures
2.9 teaspoons
2.9 tsp · 0.966 tbsp · 0.06 cups
about the size of a grape
Matcha powder typically ranges 0.3–0.42 g/mL depending on how it's packed. A firmly packed scoop weighs more.