NEW ORLEANS -- As Carnival builds toward its out-of-control crescendo of Fat Tuesday, Barry Kern and his team of float-builders and artists are already preparing for next year's parades.

One of the biggest free parties in the world fuels a multimillion-dollar industry for New Orleans and the lifeblood of businesses like Kern's studio, which has been operating for more than 50 years and makes or repurposes some 400 floats a year, or roughly a float a day, Kern said.

The Mardi Gras season -- which includes weeks of parades, fancy balls and parties leading up to the big day -- draws hundreds of thousands of visitors each year, said Kelly Schulz, spokeswoman for the New Orleans Convention and Visitors Bureau. Schulz said a recent study by Tulane University estimated the direct economic impact of Mardi Gras at roughly $144 million.

Studies estimate the economic impact at more than $500 million, said Arthur Hardy, a Mardi Gras historian. Attendance is hard to gauge, but every Mardi Gras, hotels are full, or close to it, Schultz said.

In the weeks leading up to Mardi Gras, more than 100 parades roll into New Orleans and its suburbs. The big parading clubs -- like Rex, Zulu, Bacchus, Endymion, Orpheus and Muses -- hire Kern's studio to build the floats. Smaller clubs make their own by decorating trailers with everything from paint to crepe paper.

Hardy said more than 100,000 ride in parades each year, and each rider can spend as much as $2,000 to $3,000 in fees, costumes and throws. Thousands more are spent on king cakes and the grand balls and parties, he said.

"It's a money-maker for the city, but that's not why we do it," Hardy said. "We do it because we like to celebrate. It's a free party we give ourselves and our guests."

There's big money in it. Major parade krewes often spend hundreds of thousands of dollars to have Kern's studio make their floats. Depending on whether the floats are being built from the ground up or repurposed, the price can range anywhere from $10,000 to $100,000.

Floats can be as high as 18 feet and up to 50 feet long, carry dozens of riders and be wired with electricity for lights and moving parts. Painters, artists and sculptors make props and decorations that will be attached to the floats.

It takes a year to prepare enough floats to roll through the streets of New Orleans and its suburbs, Kern said. With the revelry of Fat Tuesday at hand, Kern's preparation for Mardi Gras 2013 has begun.

"Literally, the day after Mardi Gras, we're back to work, and the process gets started almost immediately," Kern said.