NEW YORK — The economic damage from Superstorm Sandy could run as high as $50 billion, according to estimates from forecasting firm Eqecat. That would make it the second-costliest storm in US history, ­after Hurricane Katrina.

The numbers Eqecat released Thursday are more than double its previous estimate.

Eqecat said Sandy might have caused between $30 billion and $50 billion in total economic losses, including property damage, lost business, and extra living expenses. The cost to insurance companies could run as low as $10 billion and as high as $20 billion.

Power outages were more widespread than in a typical Category 1 storm, Eqecat said. Sandy knocked out electricity for more homes and businesses than any storm in history, the Department of Energy said.

The lack of subway service in New York City and blocked roadways will also push the total cost higher, Eqecat said.

Before the storm hit, Eqecat had estimated that total economic losses from Sandy could range as high as $20 billion and that losses to insurance companies could reach $10 billion.

In 2005. Katrina’s costs were $108 billion, the equivalent of $128 billion today.

Even adjusting for inflation, the high end of Eqecat’s damage estimates for Sandy would be higher than those caused by previous major storms. Andrew, which struck in 1992, cost $44 billion in today’s dollars, and the Ike storm of 2008 cost $32 billion.

Another firm that calculates the cost of catastrophes, RMS, is gathering information before it makes its first estimate. It has two reconnaissance teams surveying the damage.