Kyle Chalmers stunned the swimming world when he stormed to gold in the 100-meter freestyle at the Rio Olympics, and the Australian believes greatness awaits if he can retain his title in Tokyo next year.

The 21-year-old said he took a while to digest the one-year postponement of the Tokyo Olympics because of the COVID-19 pandemic but is convinced that the delay will only further raise the profile of the global gathering.

"After it being postponed, which we've never seen before, next year it's going to be the biggest Olympics we've ever seen," he said by phone from Adelaide last week.