Modelling from Curtin University shows lifting the GST rate from 10 to 15 per cent could add nearly $4000 to the average family budget.
Calls to lift the GST to 15 per cent could add several thousand dollars to the average household's annual budget.
NSW Premier Mike Baird has broached the idea ahead of Wednesday's federal and state leaders' meeting, but wants to put in place compensation measures to ensure low income earners aren't disadvantaged.
Figures crunched by Curtin University's economics centre and published in The West Australian show a 15 per cent GST would increase the average household's costs by $3987 a year.
Households in the bottom 20 per cent income tier would be $1755 a year worse off while the richest would face an increase of $6307 in costs a year.
Modelling by the University of Canberra's National Centre for Social and Economic Modelling estimates the average household would be up for an extra $2915 a year, the Financial Review reports.