There is no magic number as many factors contribute to the overall formula.
To determine how many clients you need,start with how much you need to earn to meet your business expenses and live comfortably.Cost of living is different from one region to another, as well as are lifestyle choices.
As I do not have employees, my target is $2,000 a week based on a 48 week year.The area in which I live in I have noticed three different price points: $65,$75,and $85 an hour.
Per week based on one hour or less grooms
$65 = 31 pets
$75 = 27 pets
$85 = 24 pets
Number of clients needed if on a 6-week schedule
$65 = 186 clients
$75 = 162 clients
$85 = 144 clients
Let's tweak that number for 4 vs 8 week clients:
$65 124 vs 248
$75 108 vs 216
$85 96 vs 192
You can see that there is a huge difference in the number of clients you need based on amount and frequency.
Being at the higher end allows me to work at a much easier pace with less stress on my body. Having clients commit to a more frequent schedule keeps the pets in more manageable coats reducing that wear and tear on me, as well as encourages a pleasant experience for the pets. While I live in one of the higher cost of living areas, the bulk of my clients are middle class working stiffs like myself.Many of which never used a grooming service before.