The record iron ore price saw Rio's operating net cashflow jump 143% to US$13.66 billion for the six months to June 30.
Free cashflow jumped 262% to a record $10.2 billion.
Underlying EBITDA was up 118% to $21 billion, while underlying earnings were $12.2 billion, up 156%.
Macquarie had forecast underlying EBITDA of $20.8 billion and underlying earnings of $12.5 billion.
Iron ore accounted for nearly $16.1 billion of EBITDA, up 109%, and $10.2 billion of earnings, up 124%.
Underlying earnings in the copper division jumped nearly 700% to $885 million.
Rio declared an interim dividend of $5.61 per share, representing 75% of earnings and well ahead of Macquarie's estimate of $4.62.
The pay-out comprises an ordinary dividend of $3.76 per share, or $6.1 billion, and special dividend of $1.85 per share, or $3 billion.
The company was in a net cash position of $3.1 billion at June 30, compared to net debt of $700 million at the start of 2021.
Rio CEO Jakob Stausholm told reporters that while government stimulus in response to COVID-19 had driven strong demand and pricing for commodities, the company remained cautious on the outlook.
"We have probably seen unsustainable levels of development [in China] in some of the months in the first half," he said.
Stausholm still isn't happy with the company's operational performance.
"This is a great set of financial results, but what we can see is where we need better operational discipline," he said.
It will be one of the new management team's four priorities.
The other priorities are advancing Riio's ESG agenda, taking important investment decisions, including today's approval of Jadar, and stepping up the company's external engagement.
Stausholm stressed the company's progress on those measures would be judged by others, but would take time.
"From my perspective, we're making really good progress," he said.
Stausholm was particularly "delighted" with the progress made on mending the relationship with traditional owners, the PKKP, in the wake of the Juukan Gorge blast last year.
"I think we are building a trusting relationship, but of course it will take time," he said.