Maximizing Individual 401(k) Contributions - Differing Amounts

[chs862]

My wife has a Schedule C business and an Individual 401(k) plan.  She has no W-2 income or any other retirement plans (SEP, Keogh, etc.) except for a Roth IRA to which she has not contributed in years.  

I am attempting to maximize her Individual 401(k) contribution so as to reduce our (filing jointly) tax burden as much as possible.  When I check the "Maximize Contribution to Individual 401(k)" box, a couple of screens later I am presented with a message that says, "Using the maximum allowable contribution, Cheryl can defer a maximum of $30,000 to a 401(k) plan."  Then I click "No" on the following screen asking about Keogh, Trad SEP, Roth SEP, etc. contributions. 

On the next screen I am then presented with a grid saying the amount for Cheryl to contribute by the plan due date is $46,318.

Why the difference?  Should she contribute $30,000 or $46,318?

[dmertz]

The $30,000 "deferral" is the employer contribution.    The $46,318 is the $30,000 plus an employer contribution of $16,318, implying that this was calculated on net profit of about $87,790.