For your first question - there is no strict revenue number that indicates it’s time to hire a project manager, because every business’s complexity grows differently. Instead, most companies hit this need when the operational load becomes bigger than the owner or lead can realistically manage.
Then, team size is mostly proportional to the revenue. Once you’re managing 5–10 people across multiple jobs, a project manager can make a difference.
As for growth, hiring a project manager doesn’t directly create revenue, but it enables growth. When a project manager standardizes processes, tracks KPIs, jobs finish on time, communication improves, repeat work increases, and the owner regains time to focus on sales, strategy, and scaling.
So while a project manager isn’t a guaranteed growth lever on day one, they remove the bottlenecks that often prevent growth and that’s usually where the return shows up.