Bobby and Whitney Are Husband and Wife and Whitney Operates

Essay

Bobby and Whitney are husband and wife and Whitney operates a sole proprietorship. They expect their joint taxable income next year to be $225,000, of which $175,000 is attributed to the sole proprietorship. Whitney is contemplating incorporating the sole proprietorship. Using the 2018 married filing joint tax brackets and the corporate tax brackets, how much current tax could this strategy save Bobby and Whitney? How much income should be retained in the corporation? (Use tax rate schedule)
Note: New Corporate income tax rate has been mentioned as "21% on all taxable income" as per the recent change.