I'm a guy who never cooks, I have no incentive to play dumb. I don't buy flour or sugar or other random raw ingredients in bulk. The closest I get is maybe a jar of coffee.
There you go, it looks like a jar with roughly 380 grams of coffee. Since you mention a jar, I assume you mean instant coffee. Your jar will be a bit taller than the packet of sugar with a similar surface area. A pound is a pound. It doesn’t matter if it’s 3300 pounds of feathers, or coffee, or sugar.