A City Council bill aims to bring more clarity when it comes to tipping cabbies with your credit card.

Councilman Dan Garodnick (D-Manhattan) will introduce legislation Monday that will call on the city to create a uniform method for cab credit card machines to calculate the final tip at the end of ride.

Taxis give riders the option of a tip based on preset percentages but depending on the software that the computer uses the amounts vary from car to car. Some machines calculate the tip on just the base fare, while others tally it from the final cost, which includes additional fees -- like nightime surcharges and tolls.

"If you put in an 18% tip, that means something different from one taxi to another," Garodnick said.

Garodnick's legislation calls for the Council to lock down a method that would be used in all yellow and green cabs. Customers will continue to have the option to input their own tip amount.

The councilman said New Yorkers don't think twice when they tap the preset options and as a result are paying a greater percentage of the fare than they realize. Cabbies may also lose out on extra money.

"It may be a small difference for a passenger in terms of cost but it adds a lot of confusion," he said.

Creative Mobile Technologies and VeriFone, two companies that provide the software for the taxi credit card machines, didn't return messages for comment.

The Taxi Workers Alliance, a union representing yellow cabdrivers, didn't return a phone call for comment.

A spokesman for the city's Taxi and Limousine Commission declined to comment but Garodnick said he's talked to the agency about the bill and expects other council members to show their support.

"This is a basic consumer protection issue," he said.