0.25 cups of olive oil is a standard measurement often used in cooking. To visualize this amount, it is about the size of a large egg.

In kitchen measures
4 tablespoons
12 tsp · 4 tbsp · 0.25 cups
about the size of a large egg
Olive oil typically ranges 0.9–0.93 g/mL depending on how it's packed. A firmly packed scoop weighs more.