The mining house, primarily owned by the Royal Bafokeng tribe, said headline earnings per share totaled 87.2 cents in the six months to end June, up from 43 cents a year earlier.
Headline EPS is the main gauge of profit on the bourse and excludes certain one-time items.
Platinum group metal production was up 1.1% at 130 278 ounces.
The company is targeting full-year output of 2.3 million tonnes milled but warned a three-week repair of its primary mill may impact the final number.
Mining firms benefit from a weaker rand because they pay expenses in the local currency while selling output in dollars.
Shares of Royal Bafokeng Platinum have shed almost 15% in the last six months, compared to a 28% decline in the Index.