How Many Grams Are in a Pound?

Actually, it’s the same – they both weigh a pound. Technically, they both weigh an avoirdupois pound, but the full name is so rarely used, most don’t even know it exists. And that’s only if you live in the U.S., which never adopted the metric system in its measurements. So, what would that pound of anything weigh in the metric world?
In 1963, the United Kingdom determined that one pound equals 0.45359237 kilograms. Since there are 1000 grams in one kilogram, multiplying .45359237 by 1000 gives you the result of 453.59237 grams in one pound. This 453.59237 is the conversion factor for grams to pounds. Multiplying the conversion factor by the number of pounds yields the grams per pounds – for example, to find the number of grams in 3 pounds, multiply the conversion factor (453.59237) by 3 (the number of pounds) for 1,360.77711 grams, or roughly 1.36 kilograms. If you are online, but don’t have a calculator handy, you can Google to find many handy converters to use. For an approximation, you can use a chart like the one below:
By the way, if you are curious, using our previous marijuana example, a standard brick of marijuana weighs one kilogram, or kilo, which is usually rounded to be 2.2 pounds.
The Troy Pound
Now, to complicate matters slightly, a pound is not always a pound – in addition to the avoirdupois pound, we have the troy pound, which is used for the measurement of precious metals, such as gold, silver, platinum, and others. Usually, troy pounds are only expressed in ounces. If it is not stated otherwise, when ounces or pounds are used in discussing precious metals, you can assume the troy system is being used.
The Troy Pound Conversion Factor
A troy pound weighs less than an avoirdupois pound because a troy pound is measured as 12 ounces, not the 16 ounces of the avoirdupois pound.
As a result, the conversion factor of grams to troy pounds is less as well – 373.2417216 grams to one troy pound.
Cooking Conversion Gets Messy
Cooking is one place where the correct conversion can make a huge difference in the results. As we have seen, grams and ounces are measurements of weight. Cups, tablespoons, and liters are measurements of volume and are not as accurate. Professional chefs use mass measurements to maintain the same flavor and look time after time. For this you would use a kitchen scale.
Even so, the conversions can be tricky. Charts like the one here are extremely useful if you find yourself needing to go from the imperial to the metric scale, or vice versa.
For the home cook, with most recipes you have some leeway in ingredient amounts. But using pounds and ounces when kilograms and grams are called for could be disastrous. Just imagine a recipe that called for 15 grams of an ingredient and you used ounces instead. Since 15 ounces would actually be 450 grams, it is doubtful this recipe will come out anywhere close to what was intended.
Grams versus Pounds
A little history might be in order to understand why there is pounds and ounces versus kilograms and grams in the first place. The pound unit is derived from the ancient Roman libra, which is where the common abbreviation of “lb” comes from. American colonists, the majority of whom came from Great Britain, brought with them the British Imperial System. France developed and improved the metric system throughout the 1700s, but the British and the colonists didn’t adapt. When America gained its independence, the Constitution gave Congress the power to fix a standard of weights and measurements. There was fear that it would be too costly to send a delegation to France to learn the metric system. Despite being allies during the American Revolution, the relationship between France and the U.S. was frosty afterwards. In 1798, France did not invite the Americans to a world convention in Paris concerning the metric system. The U.S. decided in 1821 that the system they were presently using was uniform enough and it became the standard. However, there are many instances where the metric system is used – for example, engine sizes in American made cars are expressed in liters.
Even though by 1865 Great Britain had joined the rest of Europe in adopting the metric system, today, there is a mix of systems. In 2007, the European commission declared that dual metric-imperial labeling should be used on packaging. And the British measurement of body weight uses a combination of stones (one stone is 14 avoirdupois pounds) and pounds.