The equity portion of the deal is $55.76 billion based on Time Warner Cable's diluted shares outstanding as of March 31. The company had long-term debt of $22.64 billion, according to its latest quarterly report.
The offer values each Time Warner Cable share at about $195.71 based on Charter's closing price on May 20, the companies said in a statement on Tuesday.
The deal comes at a time when the U.S. cable-and-Internet companies are looking to cut costs and gain pricing advantages through a flurry of consolidation.
Time Warner Cable's shares rose 11.6 percent to $190.50 in premarket trading, while Charter's stock was up 3.2 percent at $181.
© Thomson Reuters 2015