This comes as the actor is thought to earn $100,000 (£73,000) per episode for his role.
While co-star Balfe has a net worth of $4 million (£2.9 million), according to the website.
Much like Heughan, it is thought she also earns $100,000 (£73,000) per episode.
This means the show leads are expected to earn over $1 million (£730,000) per season of the show.
Outlander seasons 1-5 are available to watch on Amazon Prime Video now.