* Royalties vary wildly: Authors get paid a percentage of the book's price, called a "royalty." This percentage can be anywhere from 5% to 15% (or even higher in some cases), depending on the author's contract, the publisher, and the book's genre.
* Different book prices: Books cost different amounts. A paperback might be $10, while a hardcover could be $30.
* Self-published vs. traditionally published: Self-published authors set their own prices and keep a higher percentage of sales, but they also handle marketing and distribution. Traditionally published authors have a publisher handle these aspects.
Here's an example:
Let's say an author gets a 10% royalty and each book sells for $15.
* Income per book: $15 x 0.10 = $1.50
* Income for 7 books: $1.50 x 7 = $10.50
Important Note: This is a very simplified calculation. It doesn't take into account things like advances (money paid upfront by publishers), foreign rights, audio rights, or other potential income streams.
To get a better idea of how much an author might earn, you'd need to know more about:
* The author's specific royalty rate
* The average price of their books
* The number of copies sold of each book
In short, there's no way to say how much an author makes from selling seven books a year without more specific information.