Are there any payroll taxes on top of that salary number? Where I live (Belgium) there's a 33% (probably being lowered to 25% soon) social security tax paid by the employer.
NB: it drops to 2.9% (just the employer/employee portion of Medicare) after the cap, which is currently $118,500 for both 2015 and 2016. And then the employee portion of Medicare rises by 0.9% above $200K, but that's not specific to self-employment as it's the employee portion only.