How Much Would Buying Greenland Cost?

Donald Trump, who has long loved big real estate deals, has made it clear that he’s serious about striking one for Greenland.Never mind that Denmark, which controls the island, says the territory isn’t for sale.But if a negotiation were to materialize, what would, or should, the United States offer?David Barker, a real estate developer and former economist at the New York, helped us with the thought experiment.

(Barker made waves in 2009 when he argued that the American purchase of Alaska in 1867, for less than 2 cents per acre, was a bad deal from a purely financial investment perspective.) Here’s his back-of-a-napkin math for valuing Greenland, which he estimated could be worth between $12.5 billion and $77 billion.Alaska might not be the best comparison.Trump has said he wants to acquire Greenland for national defense reasons, which wasn’t the clearly defined case for the Alaska Purchase.

(In 2025 dollars, the deal was worth more than $150 million.)Consider the Virgin Islands instead.The United States bought what were known as the Danish West Indies from Denmark in 1917 for $25 million (about $657 million today) because of national defense concerns.

Greenland is obviously much bigger, but in both cases the defensive value is based on location rather than size.One way of doing the math: Barker suggested using the prices for the Virgin Islands and Alaska as starting points but adjusting them based on the nominal change in gross domestic product for the United States or Denmark to account for both inflation and economic growth.“A bigger economy can afford to pay more, and a bigger economy would probably demand a larger price,” he said.For the low-end valuation, he adjusted the purchase price of the Virgin Islands for the 500-fold growth in Denmark’s G.D.P.

since 1917.That implied a Greenland price tag of $12.5 billion.Adjusting the $7.2 million cost of the Alaska purchase for the growth in U.S.

G.D.P.produced the high end of $77 billion.Neither c...