The equation is basically the same, but corporate tax rates are used. When a corporation pays a dividend, there is no deduction. But the shareholders pay tax on the dividend. This means that profits are subject to tax twice, once at the corporate level and again at the shareholder level when dividends are paid. Many small corporations avoid this problem by paying all or most of their profits to the owners as salaries.
Reasonable salaries are deductible.
So, although the owners may pay tax on their salaries, the corporation gets a corresponding reduction in its tax. The amounts may not be equal, but it's better than the double taxation that results from dividend payments. Finally, there are two other things you should be aware of. First, the IRS has been moving to increased specialization in auditing small business taxes. This is a mixed blessing.