Mollie O’Callaghan and her world-beaters are on the cusp of swimming history.

Australia enter Sunday’s last day of competition at the Fukuoka pool assured of finishing atop the medal table – unless you ask the Americans.

United States broadcasters switched their medal tally mid-meet from the traditional measure of golds won, to overall medals won.

That change puts them on top with 31 overall medals to Australia’s 20 – but American swimmers have won just four golds to Australia’s 13.

“It has always been gold medals,” Australian freestyler Kyle Chalmers said.

“So this year it will be no different.

“They (the United States) will always probably try and find a way to sneak it to make it look like they’re the better team.

“But this year, we have done it.”

Australia’s 13 golds so far equals the nation’s best haul at a single world championships – at the 2005 and 2001 editions.

China are next-best with five medals but with only seven finals to come on Sunday night, the bragging rights belong to Australia.

The Dolphins have only led the medal count at one previous world championships, also in Fukuoka, in 2001.

O’Callaghan has five gold medals and has featured in four of Australia’s five world records at the meet.

The 19-year-old has equalled Libby Trickett’s women’s national record of five golds at a single world championships.

One more on Sunday night in the women’s 4x100m medley relay and O’Callaghan will share Ian Thorpe’s Australian record for most golds at a single championship.

“I am too busy to think about it, to be honest,” said O’Callaghan, who has been racing on all but one of the eight days of competition.

“I have just had a lot going on this week and I have just got to maintain it and be as professional as possible.

“Just sticking around with the team and keeping it quite closed has helped me.

“Instead of (being) on social media doing this and that, I have just tried to keep it as composed as possible.”

On Sunday night, Sam Short is a chance in the men’s 1500m freestyle, as are Shayna Jack and Emma McKeon in the women’s 50m freestyle.

The championships end with two relays – men’s 4x100m medley and the women’s 4x100m medley.

Australia’s women are hot favourites in the 100 medley which looms as a fitting finale for the nation’s triumphant meet which began when Short won the first medal race last Sunday.