I measure in terms of the entire book.
I'll typically produce a rough outline over a week-long vacation. That's the hard part. So I set my career aside, take a vacation, and concentrate entirely on it. The story itself, in perhaps 10 pages or so. Sometimes much less. 3 to 10 pages, from beginning to end.
I might tell the story to a bunch of friends around a campfire or on a nature hike. If they don't love the ending, the story dies then and there.
Then I'll expand that into around 200 pages of paraphrased scenes, sample dialogue, sample interactions between characters to ensure they work plausibly together.
Then maybe six to seven months to write the book, and that's with constantly going back to ensure pacing, consistency, continuity. I'm currently writing very long books that develop slowly. My next project might have much shorter books. Whatever the stories demand.
Then one or two months of editing. Which I do manually. No assists. Except for spellcheck. But only as a first pass, because spellcheck sucks. The real spellchecking I do manually as well. With a bound/print unabridged dictionary. An American English dictionary for the most part, though I'll sometimes fall back on the OED.
I set it aside for a few weeks. Then I read it. If I like it, I might post it. If not, I don't.
So, for the stuff I'm writing now, about a year.