Solo 401k Maximum amount allowed for Employer Contribution

I get paid as an Independent IT/Management contractor directly in my bank account for a European based Startup. [ I do not get 1099 as its a European startup with nothing in US]

 

I will report this in Schedule C. 

I have opened a SOLO 401k with Nabers group

 

Lets say my income is 100,000 [ no expense incurred - this is total what I get in my account at the end ]

I can pay as an employee 22,500

Question 1

What do I pay as maximum as an employer ?

Is it [100000 - (15.3*.05*100000) ] * 20%   ?

Is it [100000 - (15.3*.05*100000) ] * 25%   ?

Is it [100000 - (15.3*.05*100000)  -22500 ] * 20%   ?

Is it [100000 - (15.3*.05*100000)  -22500] * 25%   ?