Vudu uses streaming, so it uses around 5–7 GB for a 1080p movie and probably about 10–13 GB of data for a 4k movie. A 1080p blu-ray can hold up to 100GB, a 2-hour movie is typically 40 GB or so, and a 4k Blu-ray can hold up to 100GB, with movies often in the 50–70 GB range.