The correct uses for “based off of” or “based on” are interchangeable. They both refer to information or a concept with foundations from elsewhere. However, there is a right and wrong way to use them in certain circumstances. While it’s becoming more frequent to hear them interchangeably, the preposition will dictate which one is best.
Meaning of “Base,” “Off of” and “On
A “base” is a noun that indicates a foundation, basis, or support on which something rests. Without this “base,” nothing that came after it may or may not be possible. For instance, every structure, movie, book, painting, statue, sculpture, or idea has a foundation that began elsewhere.
The prepositional phrase “off of” suggests something is inoperable or has stopped functioning. It also indicates distance or something away from its support. Conversely, the preposition “on” denotes something that is on top of its support; that it’s operable and functioning.
Combining “Based” with “Off of” and “On”
Depending on the subject or circumstance, “based off of” and “based on” are very appropriate synonyms for each other.
Based on a book of the same name, the movie, “Soylent Green” depicts a dystopian future.
Based off of a book of the same name, the movie, “Soylent Green” depicts a dystopian future.
Since there is both a movie and book named “Soylent Green,” saying the movie is “based on” the book is correct because it follows the basic storyline. However, it’s also correct to say “based off of” because the movie is separate from the book and it veers away from certain details.
However, there are times when either phrase can sound a little strange.
American diets are based on foods high in fat, protein, sugar, and cholesterol.
American diets are based off of foods high in fat, protein sugar, and cholesterol.
While you could say both, using “based off of” in this context doesn’t sound right. The support of the American diet isn’t away from foods high in fat, protein, sugar, and cholesterol. In fact, it’s the foundation of the diet, in which case “based on” is correct.
In many situations “based off of” and “based on” can be synonyms for one another. However, there are going to be moments where using one will sound a little stranger. Therefore, remember “on” is working with its support and “off” is away.