Social Security is capped at $184,500
SS tax is 6.2% for individual and 6.2% for employer.
Employee A makes $184,500. $11,439 paid by individual and $11,439 paid by employer. $22,878 total.
22,878/184500=.124 or 12.4% tax.
Employee B makes $1,000,000. SS is capped at $184,500. $11,439 paid by individual and $11,439 paid by employer. $22,878 total.
22,878/1,000,000=.022 or 2.2% tax.
So someone making a million dollars would only have to give up 1.1% to SS tax and their employer 1.1% SS tax.
They will both pay the exact same amount into SS but the percentage isn't as high because $815,500 of the million is not getting taxed.