Sentencing will take place at a later date.
The jury cleared Hamid of two further counts of soliciting to murder, with regard to speeches, and another charge of possessing terrorist articles.
Hamid, who came to the UK when he was five, was also found not guilty of providing weapons' training at camps.
Another man, Mousa Brown, was cleared of receiving or providing training.
Peter Clarke, assistant commissioner for specialist operations at London's Metropolitan Police, said: "Hamid and Ahmet are dangerous people who between them carried out the recruitment, grooming and terrorist training of young men."
Prosecutors said Ahmet and Hamid trained the men in sessions disguised as camping or paintballing trips in rural locations around Britain.
An undercover officer who helped secure the convictions once heard a conversation in which Hamid boasted: "Fifty-two, that's not even breakfast for me", referring to the July 7 2005 attacks on London in which 52 people died.
"Hamid directed his recruits through military exercises, teaching them how to defend themselves against armed ambush. This was not innocent activity taking place on a camping weekend," said Clarke.
He said: "Hamid's links to men convicted of carrying out the [July 21] attempted bombings in London shows the depth of his involvement in terrorism."
During the trial, the jury was shown pictures of the men practising firing positions using sticks instead of guns, pretending to throw grenades and crawling through streams.
The day after the July 7 attacks, Hamid sent a phone text message to one of the July 21 conspirators saying: "We fear no one except Allah. We will not change our ways. We are proud to be Muslims".
Ahmet had discussed giving TV interviews in which he had been referred to as al-Qaeda's number one in Europe.
"So they are basically depicting me as ... you know one of the biggest terrorists in, in not only the UK but in the whole of Europe," Ahmet told CNN television.
Hamid and Ahmet were arrested in London in September 2006 after a months-long intelligence operation.