How big would a $1 trillion platinum coin be?

Mint the coin. Mint it.

The proposal that the president should order the US Treasury to mint a trillion-dollar platinum coin—a ploy to sidestep the debt ceiling, which will prevent further borrowing sometime in February—has generated a ton of hype and garnered some support online. Nobel-prize winning economist Paul Krugman is for it, as is Business Insider’s Joe Weisenthal. Others, like The Guardian’s Heidi Moore and Quartz’s Tim Fernholz, consider the idea absurd.

It’s highly unlikely that Obama would even consider the scheme. But the real question about the platinum coin is: What would the thing look like? And most importantly, how big should a trillion dollar coin be?

A coin can be any size. The Treasury gets to decide a coin’s worth, and the value of the metal that comprises the coin doesn’t have anything to do with its value in currency. Say the Platinum Trill (our name for the coin) were the size of a standard circulating US coin. Here’s how much the metal would cost:

Or, we could pick the size in a more sophisticated way. There is a very rough relationship between the face value of a coin and the raw value of its metal. You could extrapolate that relationship to $1 trillion like so:

The result is a coin made of $60 billion of pure platinum that weighs about 500,000 pounds, and, if it had the same proportions as a quarter, would be 10.5 yards in diameter and a little over two feet tall. Not exactly pocket change.