Writing is mostly a long-term profession.
For most professional writers, writing is a long-term prospect.
You are unlikely to make much money from one book, or five.
Of course, unlikely is not the same as impossible.
What makes a professional career work:
A reader reads one of your books, enjoys it, searches for another one, and finds one.
So to make a steady, livable income, you (probably) have to write a bunch of books that readers enjoy.
It is possible that your first book will bring in enough money to live on.
The likelihood depends on:
- Your skill at writing books that readers enjoy
- Your skill at reaching readers who would enjoy your books
- Your skill at negotiating a publishing contract
You have not demonstrated any of those yet.
On the other hand, nobody ever demonstrated those skills before their first successful book.
The average novel.
As for the earning potential of the average novel,
the answer likely depends on which average you have in mind.
I think median income from a novel is zero.
Most novels are never published.
I suspect that the median income from a published novel is also zero.
Rumor has it that seven out of ten never earn out the full advance.
So for most traditionally published novels,
the advance is the only income you will receive.
Alternatives to quitting your day job.
Of course, quitting your current unpleasant job in order to write full time is just one option. Some others:
- Get a job that you like. Or at least a job that you hate less.
- Get a job that gives you more time to write, as long as it provides sufficient income.
How to assess the risk.
For risky ideas like quitting your day job, I like to ask myself three questions:
- What is the worst thing that could happen?
- What is the best thing that could happen?
- What is most likely to happen?
Then pay attention to your answers.
Heck, if you can survive the worst thing that could happen,
maybe it ain't such a huge risk for you after all.
And revisit the questions as you learn more about the possibilities.