You pay tax based on your companies income.

Taxable income (R)-----Rates of Tax (R)​
​0 - 67 111 ------------ 0% of taxable income​
67 112 - 365 000​ ------7% of taxable income above 67 111​
365 001 - 550 000 -----20 852 + 21% of taxable income above 365 000​
550 001 and above -----59702 + 28% of the amount above 550 000​

From: http://www.sars.gov.za/ClientSegment...s/default.aspx

I hope this information is correct.