Pokie machine operators should be forced to display the odds of winning and losing on every machine, a mathematician says.

Victoria University's Tristan Barnett, who has spent years calculating poker machine betting odds, is calling for legislation to be changed to protect consumers and help problem gamblers.

His latest research, set to be published in the Gaming Law Review and Economics, has found in one hour of play on a $1 poker machine, at 18 spins per minute, the expected loss for a player is $108.

But he says there is a 35 per cent chance of losing more than $300.

"Giving those extreme statistics might change the decision of the consumer and how long they might actually play for," he said.

Dr Barnett says statistics on profit/loss odds are currently too hidden.

"The workings or the mechanics of the poker machine are driven by the mathematics and consumers are not given that information and that information is not even available," he said.

"Poker machines are the only casino game where you can't calculate the complete set of mathematics - the information is just not available."

Dr Barnett says pokie machines mislead consumers by only showing how much gamblers have won and not how much they have lost.

"You've got to take into account the amount you've actually put into the machine and the amount that's actually being returned - they need to be combined together with the total profit," he said.

"Say if a player was to bet $10 on a machine and if they were to get a return of $7, the machine would actually display a win when it's actually lost money.

"The machine should actually indicate when they've actually won money and when they've lost money.

"It's not realistic - it's actually misleading and unfair."

Dr Barnett says even though pokie machines have to show the per cent house margin - how much the machine will take in the long run - that is not enough to properly inform consumers.

He says the per cent house margin is generally about 10 per cent, but it is as high as 17 per cent in New South Wales.

He says manufacturers deliberately avoid properly informing consumers.

"It's to do with the marketing. Obviously the manufacturers want it to look as if these machines will be a good experience and they tell the consumers they're winning as much as possible and they're not actually indicating how much they're losing," he said.

"And, of course, giving the information that losing more than $300 is a high per cent chance isn't a very good incentive to play the machine.

"So to some extent it is misleading and consumers are being taken advantage of."

The chief executive of the Australian Gaming Machine Manufacturers Association (AGMMA), Ross Ferrar, says its members' machines display all the necessary information required by law.

"Our members' gaming machines comply with all the standards that are required by states," he said.

"It varies state by state."

Mr Ferrar points to Victoria, where certain information is required on player screens, like the probability of winning top five, and he says AGMMA's members comply with such rules.

The ABC contacted Clubs NSW for comment.