Looking at submission guidelines from a variety of CBA publishers at the Faith, Hope & Love website, it looks like 90,000 words is a good all-around target for a novel length. But you have to write more than 90k words to get 90k words.
I like Steven King’s axiom for 1st draft versus 2nd draft word counts:
2nd Draft = 1st Draft – 10%
So, to target 90,000 final draft words, write 100,000 words!