400 grams of long-grain rice is 14.1 oz (400 g) in weight and has a volume of 1.99 cups (471 mL). It is about the size of a water bottle, which you can see in the photo next to a golf ball, a soda can, and a smartphone.

In kitchen measures
1.99 cups
95.5 tsp · 31.8 tbsp · 1.99 cups
about the size of a water bottle
Long-grain rice typically ranges 0.75–0.92 g/mL depending on how it's packed. A firmly packed scoop weighs more.