Akilov's defence lawyer, Johan Eriksson, argued that his client be given a more lenient sentence because he was cooperative with the investigation following the attack.
Akilov hijacked a beer truck outside a restaurant in central Stockholm on April 7 a year ago and sped about 500 metres (yards) down a pedestrian street, ploughing into shoppers before crashing the vehicle into a department store.
"It is not believed that he belonged to any terrorist organisation", chief judge Ragnar Palmqvist said but added that an offender could be found guilty of terrorist offences if the crime were severe enough.
Rakhmat Akilov is being apprehended in Marsta, North of Stockholm after the lorry attack in Central Stockholm on April 7, 2017.
Court sketch shows Rakhmat Akilov questioned about the terror attack in Stockholm on April past year, during the trial in district court in Stockholm, Sweden February 20, 2018.
Inmates serving life sentences in Sweden stay behind bars for an average of 16 years.
If the person was one to two meters away from the truck, it is deemed attempted murder.
Witnesses said the truck drove straight into the entrance of the Ahlens Department Store on Drottninggatan, the city's biggest pedestrian street, sending shoppers screaming and running. He then fled via the subway but was arrested hours later.
ISIS sympathizer given life sentence for deadly Sweden truck attack
He was found guilty of five counts of terror-related murder, 119 counts of attempted murder and 24 cases of endangering the life of others.
He later went underground to avoid expulsion and worked odd jobs in construction.
The truck displaced lion-shaped boulders, similar to roadblocks that were put up in several European capitals after another truck attack killed 12 people at a Christmas market in Berlin in 2016.
He came to Sweden in 2014 and applied for asylum, claiming he had been persecuted.
Soon after the attack, Prime Minister Stefan Lofven said Sweden would stick by its open, liberal values.
Before stealing the truck, Akilov swore allegiance to the IS.
During the trial, evidence showed how Akilov used 53 Sim cards and social media - including WhatsApp, Telegram, Viber, Facebook and Zello - to communicate with others about his activities.
While the text messages indicated Akilov consulted with his contacts on how to carry out his attack, prosecutors have insisted that he acted alone. It was not clear whether the group had accepted his offer.