In this age of austerity a beer drinker needs to know he or she is getting a full pint.

You know what happens when you belly up to some bars. That “pint” turns out to be 14 ounces or even less once the head settles. It’s not the 16 ounces you purchased.

Now there’s relief. A Colorado company has created “The ‘Piaget’ Beer Gauge.” The slick little helper is the size of a business card and made of stiff, waterproof plastic. It has a beveled edge to match the side of a standard U.S. pint beer glass. The gauge on the side shows if you are getting 15, 14, 13 or fewer ounces of liquid gold when that beer appears on the bar. It also shows what percentage of the entire pint you are missing. This feature should spare beer-addled minds the hassle of running the numbers.

The simple concept is actually quite illuminating. The shape of a pint glass makes it look close to full even when it is two ounces short. The secret is the glass width at the top. That’s where volume is gained or lost.

At 14 ounces, for example, you’re getting shorted 13 percent. At 13 ounces, you’re losing out on 19 percent of capacity.

Don’t feel bad that you’ve knocked back beers all these years without realizing how much you’ve been shorted. A scientist by the name of Piaget studied the human inability to distinguish identical volumes in different sized containers. In the spirit of Piaget, the beer gauge company’s motto is “do not get short poured again at a bar.”

Knowledge is, of course, power. But how do you inform your bartender you’re getting shorted? “It’s a good way to get your next beer spit in,” one of my colleagues noted.

Something to think about.

The beer gauge is available online for $2 plus shipping. Go to thebeergauge.com.

scondon@aspentimes.com