Is Rio Tinto becoming a better copper investment than BHP?

Copper is becoming an increasingly important commodity as the world invests in electricity networks, data centres, and new technologies.

And I think some of the biggest beneficiaries could be the mining companies capable of supplying more of it.

Two Australian mining giants stand out to me, with both investing heavily in expanding their copper operations.

But could one now offer a better investment opportunity than the other? Here's what I think.

Rio Tinto Ltd (ASX: RIO)

One of the biggest reasons I'm becoming more optimistic about Rio Tinto's copper outlook is the progress being made at its Oyu Tolgoi mine in Mongolia.

The company has spent years developing the mine's underground operations, and that investment is now starting to deliver significant production growth.

According to its October production update, Oyu Tolgoi produced 312,000 tonnes of copper during the first nine months of 2026, an increase of 29% compared with the same period last year.

And there's still plenty of room for production to grow. Rio Tinto expects Oyu Tolgoi to produce an average of approximately 500,000 tonnes of the red metal annually between 2028 and 2036.

I think that's an exciting prospect for a mine that is already operating and gradually increasing its output.

After years of heavy investment, Rio Tinto is approaching a period where Oyu Tolgoi could become a much larger contributor to its earnings, especially if copper prices remain strong.

Of course, production across the company's entire copper business isn't growing at the same pace. Group output increased just 1% during the first nine months of 2026.

But looking ahead, I think the continued expansion at Oyu Tolgoi gives the company a good opportunity to increase its copper earnings over the next few years.

And with BHP expecting lower copper production in FY27, that could give Rio an advantage in the near term.

BHP Group Ltd (ASX: BHP)

I'm also very bullish on BHP, which remains the world's largest copper producer.

In FY26, it produced approximately 1.95 million tonnes of copper, with the commodity contributing more than half of its underlying EBITDA.

That demonstrates how important the base metal has already become to the business.

But BHP is facing a period of lower production. Management expects copper output of between 1.65 million and 1.8 million tonnes in FY27, largely reflecting declining ore grades at its Escondida mine in Chile.

This is where I think Rio has an advantage over the shorter term. While Oyu Tolgoi continues ramping up, BHP is working through a period of weaker production before its next major investments begin contributing.

However, looking further ahead, there's plenty to like about BHP's plans. The company is progressing a new concentrator at Escondida and expanding its copper operations in South Australia.

In its FY26 results, management stated its belief that its development pipeline could increase attributable copper production by approximately 40% by FY35.

I think that's an enormous opportunity for a business already producing the red metal at such a substantial scale. And BHP's established iron ore operations provide considerable cash flow to help fund those ambitions.

Foolish takeaway

I would be happy buying both BHP and Rio Tinto shares today.

BHP remains one of my favourite long-term ASX investments, and I think its expanding copper business could become significantly more valuable over the next decade.

But if I were choosing based on copper production growth over the next three to five years, I might lean towards Rio Tinto.

Oyu Tolgoi is already delivering strong growth, and I think the next stage of its expansion could be rewarding for shareholders.

That gives Rio Tinto a slight edge for me today, although I'd be very comfortable owning both.

The post Is Rio Tinto becoming a better copper investment than BHP? appeared first on The Motley Fool Australia.

Motley Fool contributor Grace Alvino has no position in any of the stocks mentioned. The Motley Fool Australia's parent company Motley Fool Holdings Inc. has no position in any of the stocks mentioned. The Motley Fool Australia has recommended BHP Group. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Scott Phillips.

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