J.B. O’Reilly’s owner Paul North. Photo: Teri Campbell

Staff at popular Irish pub Rosie O’Grady’s say Perth revellers will drink four times more Guinness this St Patrick’s Day than on a normal weekend.

Irish pubs across Perth are preparing for the biggest day on their calendar this Saturday.

Northbridge watering hole Rosie O’Grady’s and JB O’Reilly’s in West Leederville have made sure they’re ready for the big weekend.

“We have 60 kegs of Guinness ready for this weekend,” Rosie O’Grady’s general manager Scott Fraser said.

Guinness is the drink of choice for St Patrick’s Day. Photo: Teri Campbell

“On a normal weekend we would only need 15.

“We predict to be at full capacity from 12pm until closing for St Paddy’s Day. Usually we won’t reach full capacity until 8pm.”

JB O’Reilly’s general manager Sharon Munnelly says staff expect a 50 per cent increase on the sale of Guinness for the day.

“We have 20 taps of different beers. Normally 40 per cent of those sales will be Guinness but for St Patrick’s Day we predict it will increase to 90 per cent.

“We are expecting to be at full capacity from 10am until closing.”

According to the 2016 Census, over two hundred thousand people in Western Australia have an Irish background.

Irish is the third most common ancestry in Perth.