More Canadian bar owners may soon be giving slightly smaller liquor shots to customers because of a costly discrepancy between Canadian and U.S. systems of measurement.

The owners of the Vancouver's Loose Moose bar performed an audit earlier this year to find out why they were not getting as many shots out of a liquor bottle as they expected.

They discovered that the culprit was the common shot glass.

"The shot glasses [we] were using were made by an American company and they were based on an American ounce," said Loose Moose co-owner Kyle Tweter. "So they were too big."

Although the Canadian (imperial) quart is about 20 per cent larger than the U.S. quart, the U.S. divides its quarts into 32 fluid ounces while the Canadian quart is divided into 40 fluid ounces.

And in converting to metric, Canadian provincial liquor authorities use the Canadian measurement of just over 28 millilitres to replace the ounce, while the U.S. glasses contain 30 millilitres.

New business opportunity

That makes the Canadian one-ounce shot about 93 per cent of the size of the U.S. shot, meaning that only 38 U.S. shots can be poured from a Canadian 40-ounce bottle.

For bars that might pour thousands of shots a year and for restaurants that also sell a lot of liquor, it adds up when they use U.S. shot glasses.

"The average restaurant would purchase about $2,500 a month in hard alcohol," said Tweter. "They would save upwards of $2,000 a year."

A bar that spends $20,000 on liquor every month would save $16,000 a year, he said.

Tweter and co-owner Dan Wilson sought out a Canadian-sized shot glass, but they could find nothing in this country and decided that products available in Britain were too expensive to buy and ship.

That prompted them to start manufacturing their own glass, called the Can-Pour.

Two restaurant supply companies are now distributing the product across Canada, they said.

With files from the CBC's Renee Filippone