The first is next Thursday on Sky News and Channel 4, when the Prime Minister and Mr Miliband will be interviewed separately and then answer questions from a live studio audience.
On April 16, the Labour leader is to appear in a BBC debate with counterparts from Ukip, the SNP, the Greens and Plaid Cymru.
The final encounter will be a special Question Time on BBC1 on April 30 featuring the Tory leader, Mr Miliband and Lib Dem Nick Clegg answering questions separately from a studio audience.
Labour immediately branded Mr Cameron a "coward" for avoiding a head-to-head debate with Mr Miliband.
"The cowardice of David Cameron is still preventing the head-to-head debate on the 30th. Cameron is now in the ludicrous position of saying he will attend the same programme and take the same questions from the same audience as Ed Miliband, but will not debate him face to face," a source said.
But a Tory source insisted they had secured an even better deal than they were hoping for.
"If anything this is an improvement on the deal we were offered last week. The PM has always believed too many debates would suck the life out of the campaign," they said.
"In all these formats, we are confident the choice between competence and chaos will be clear."
The final line-up follows years of wrangling between parties and broadcasters over whether and how to repeat the debates from the 2010 election campaign - which saw Gordon Brown, David Cameron and Nick Clegg square up three times.
Mr Cameron rejected previous proposals on the basis they did not include the Greens, and insisted the sessions should not take place during the short election campaign that starts on March 30.
"The other parties have now got to stop running away from this and agree to the debate that the broadcasters have now offered," Cameron said. It was a response that some considered ironic after what they saw as weeks of hesitation by the prime minister.
Green party leader Natalie Bennett - whose party was not included in some early TV proposals - said: "I welcome the fact that we now finally appeared to have reached the end of the debate about the debates.
"David Cameron's intransigence has delayed this process, and taken away space in which we might have been debating the future of Britain - our low-pay, insecure jobs, the privatisation of our NHS, the urgency of cutting carbon emissions.
"Nonetheless, we can now move on, in the new age of multiparty politics in Britain."
A joint statement from the broadcasters today said: "We're delighted that there will be a debate with all the party leaders during the election campaign. The debate on April 2 will build on the success of the 2010 TV debates which were so highly valued by viewers.
"We're very pleased to be able to offer viewers an extensive range of programmes, across the four channels, featuring the party leaders interacting directly with voters during the campaign."