The Barefoot Investor has warned Aussies to 'plan for the worst' ahead of the Reserve Bank's interest rate meeting on Tuesday.

Finance guru Scott Pape said families must 'brace for a slap' amid rising concerns the RBA will have 'no choice' but to lift the cash rate.

'Right now, fuel and fertiliser costs are pushing the price of nearly everything higher. And when inflation climbs above 3 per cent the Reserve Bank lifts rates,' Pape said.

'But here's the problem: even stripping out fuel and food, inflation is already running above 3 per cent.

'So brace for a slap. Probably several. Think of it as an episode of Married at First Sight, except the contestants all bought their homes on Albo's 5 per cent deposit scheme.'

Pape said he is guided by the principle, 'hope for the best, plan for the worst,' but warned that once prices go up, it will be a struggle to bring them back down.

It comes as a poll of economists found 27 of the 36 industry experts predict there will be more interest rate pain for households at Tuesday's meeting.

If the RBA chooses to hike interest rates, it will be the board's third rise in the last three meetings and will reverse the cash rate relief in 2025.

During its first two meetings of the year in February and March, the RBA lifted the cash rate by 50 basis points to 4.10 per cent.

According to Finder, Aussies with an average home loan of $736,259 will have to fork out $2657 more per year on their mortgage if there is a third 25 basis point hike this week.

While many believe the rate hike is inevitable, some have warned the board could make a 'historic mistake' if they chose to lift the cash rate as it would 'ignore the key economic indicators' that show the Australian economy is already in a weakened state.

'If the RBA does raise interest rates tomorrow this it would most likely plunge Australia into a 'recession we don't have to have' – if we aren't already in one,' CEO of Roy Morgan, Michele Levine, said. 

'The underlying level of inflation in the economy was unchanged in March despite the damaging headlines and media commentary which accompanied the release of the ABS inflation data. 

'Once volatile and short-term price changes were stripped out – there was no increase to inflation in the real economy.'

Roy Morgan Business Confidence for April, which was released on Monday,  shows the index crashing 14.2 points in April to a record low of only 76.5.

This marks below the previous record low reached at the onset of the COVID-19 pandemic in 2020 of 76.9.

The survey also shows 61.3 per cent of businesses expect 'bad times' for the Australian economy over the next year, and 73.4 per cent expect 'bad times' for the economy over the longer-term of the next five years. 

Queensland University of Technology adjunct professor and personal finance expert, Noel Whittaker, also said an increase to interest rates now would be 'economic madness.'

'To me, it would be economic madness to raise rates in this time of uncertainty,' he said.

'And even though a recession is forecast, it's not happening yet, so they won't be dropping them.'