In a monopsony labor market, how does the employer decide on the optimal number of workers to hire?

In a monopsony labor market, there is only one employer for a particular type of job, which gives that employer significant control over wages and hiring. The employer decides on the optimal number of workers to hire by comparing the cost of hiring each additional worker to the additional benefit that worker brings to the company. This means the employer looks at how much more output or profit each new employee can generate and weighs that against the wage they would have to pay. For example, if hiring one more worker increases production enough to cover their wage and more, the employer will hire that worker. However, if the cost of hiring exceeds the benefit, the employer will choose not to hire that worker, ensuring they maximize their profits.