Here is how some of the major costs could break down:

INDIVIDUAL LIABILITY: $14.3 billion

Hundreds of thousands of individuals and businesses have sued BP, with claimants ranging from fishermen and oyster men to hoteliers and restaurateurs to tourist businesses. BP in August 2010 set aside $20 billion to cover damage claims in the Gulf Coast Claims Facility. The facility paid out nearly $6.5 billion on over 200,000 claims, and BP in March agreed to a settlement that commits an additional estimated $7.8 billion for about 125,000 claims. BP has acknowledged that figure could increase, and a U.S. judge must give final approval to the deal.

OPERATIONAL RESPONSE: $14 billion

As the responsible party for the spill under the Oil Pollution Act, BP has so far spent $14 billion, including the cost to cap the mile-deep Macondo well, hire hundreds of marine vessels to skim oil slicks and clean up hundreds of miles (km) of oil-soaked shoreline in five U.S. states.

CIVIL PENALTIES: $5.4 billion to $21 billion

The federal Clean Water Act lets the U.S. government seek fines up to $1,100 per barrel of oil spilled. Assuming that 4.9 million barrels were spilled, a fine could reach $5.4 billion. But if gross negligence or willful misconduct is found, the fine rises to $4,300 a barrel. The resulting bill would be $21 billion. Thomas Claps, litigation analyst for Susquehanna Financial Group LLP, has pegged likely Clean Water Act fines at between $7 billion and $10 billion. BP has set aside $3.5 billion to cover Clean Water Act violations.

CRIMINAL PENALTIES: $5 billion to $15 billion

Weeks after the rig explosion, U.S. Attorney General Eric Holder took the unusual step of confirming that the Justice Department had launched a criminal probe into the spill. The U.S. government has not filed any criminal charges against BP or its Macondo partners. But in January, Martijn Rats, head of European oil research at Morgan Stanley, put the cost of potential criminal penalties at $5 billion to $15 billion. Thomas Claps at Susquehanna Financial Group estimated criminal penalties at between $5 billion and $10 billion.

ENVIRONMENTAL DAMAGE: $5 billion

The U.S. government is undertaking a multi-year study of the ecological damage caused by the spill in a process called a Natural Resource Damage Assessment. Louisiana bore the brunt of the BP Plc spill's damage - about 650 miles of its coastline were oiled, versus 174 miles in Florida, 159 miles in Mississippi and 90 miles in Alabama. It could be years before the damage assessment is complete, and coastal states could choose to settle in the meantime. Morgan Stanley's Rats pegged the cost of environmental damage and recovery at $5 billion. Some Gulf Coast state officials have criticized that figure as too low.

(Reporting By Chris Baltimore; Editing by Alden Bentley)

Stocks treated in this article : BP plc, Halliburton Company, Transocean LTD