A teaspoon of ground cinnamon is a small, light dusting of spice. It is about half the size of a cherry when poured into a loose pile.

In kitchen measures
1 teaspoons
1 tsp · 0.333 tbsp · 0.021 cups
about half the size of a cherry
Ground cinnamon typically ranges 0.45–0.6 g/mL depending on how it's packed. A firmly packed scoop weighs more.