Announcer

Welcome to BrainStuff from HowStuffWorks.com, where smart happens.

Marshall Brain

Hi, I’m Marshall Brain with today’s question. If you took all of the gold in the world and put in one place, how much would there be? It’s amazing, but the total amount of gold in the world is a surprisingly small quantity. Here’s how you can calculate the total amount that’s available. If you look it up, you’ll find that the annual worldwide production of gold is something like 50 million troy ounces per year. Gold has a specific gravity of 19.3, meaning that it’s 19.3 times heavier than water, so gold weighs 19.3 kilograms per liter. A liter is a cube that measure 10 centimeters, about four inches, on a side.

There are 32.15 troy ounces in a kilogram. Therefore, the world produces a cube of gold that’s about 4.3 meters, or about 14 feet, on each side every year. In other words, all of the gold produced worldwide in one year could just about fit in the average person’s living room. This cube weighs 1,500,000 kilograms or about 3 million pounds. It would be worth about $30 to 40 billion at today’s prices. Figuring out the total amount of gold that’s been produced by man in all of eternity is a little harder. To get at some kind of estimate, let’s figure that the world has been producing gold at 50 million troy ounces a year for 200 years.

That number is probably a little high, but when you figure that the Aztecs and the Egyptians produced a fair amount of gold for a long time, it’s probably not too far off. 50 million ounces times 200 years equals 10 billion ounces. 10 billion ounces of gold would fit into a cube roughly 25 meters, or about 82 feet, on a side. Consider that the Washington Monument measures 55 by 55 feet at the base and is 555 feet tall, that means that if you could somehow gather every scrap of gold that man has ever mined into one place, you could only build about one third of the Washington Monument with it.

Platinum is even more scarce than gold. Only 3.6 million troy ounces are produced every year. Its specific gravity is 21.45, and it was discovered in the 18th Century, not in 3,000 BC. If you assume that the world has produced 3.6 million ounces per year for 50 years to estimate the total worldwide supply, all of the platinum in the world would fit into a cube about 20 meters on the side. In other words, all the platinum in the entire world would easily fit inside the average house.
Do you have any ideas or suggestions for this podcast? If so, please send me an e-mail at podcast@HowStuffWorks.com.