The study also showed Australia's traditionally strong swimming team, which produced just one gold medal in a chaotic London campaign, would have won seven golds
China is on track to return to the top of the medals table at the Rio de Janeiro Olympics next year ahead of the United States and Russia, according to a benchmark study released by the Australian Olympic Committee on Wednesday.
The annual study, which analyses the results in Olympic events at world championships and other elite events, gave China 39 gold medals based on the performances of its athletes in 2015.
The United States, table-toppers in London in 2012, would have won 35 gold medals ahead of Russia (25) with Japan the best of the rest behind the three sporting superpowers on 18.
Rio hosts Brazil, meanwhile, would have finished outside the top 20 on the medals table with just three golds.
Britain, which benefited from the traditional host nation bump to finish third in London, would have been joint fifth with neighbouring France on 15 golds, while Australia and Germany tied for seventh on 13 in the study.
That tally would nearly double Australia's tally of seven golds in London, where a 10th place finish on the medals table gave the sports-mad country one of its most disappointing Games of recent years.
Kitty Chiller, Australia's Chef de Mission for Rio, was encouraged by the data and said the AOC's target of a top five finish next year was a viable, if tough, goal.
"We have moved from a total of seven gold in London in 2012 to 13 gold this year," she said in a news release.
"Overall we've had a better year, the gold medal tally is a tremendous improvement and the signs are good for Rio.
"Fifth to eighth position on the medal tally is extremely tight and we are still aiming for that fifth spot in Rio if everything goes our way."
The study showed Australia's traditionally strong swimming team, which produced just one gold medal in a chaotic London campaign, would have won seven golds.
Russia's tally included two golds from track and field. The Russian Athletics Federation (ARAF) was suspended last month following a report that exposed widespread, systematic state-sponsored doping and related corruption.
Russian athletes are therefore set to miss the World Indoor Athletics Championships in the United States in March and face a race against time to be cleared to compete in the Olympics in Rio de Janeiro in August.