Pedophile Rolf Harris will likely arrive at Southwark Crown Court on Friday in a chauffeur-driven car but leave in a prison van.

The 84-year-old is about to find out how many years he’ll be spending behind bars, with legal experts suggesting he could be jailed for up to a decade.

Harris was earlier this week convicted of 12 indecent assaults against four girls in the UK between 1968 and 1986.

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Dozens of other women in Britain, Australia and New Zealand have revealed they too were abused by the predator over the past 50 years.

Most of the charges against Harris carry a maximum sentence of two years.

But he could be jailed for five years for attacking a seven or eight-year-old in the late 1960s at a community centre near Portsmouth.

She’d gone on stage to get the performer’s autograph when Harris “aggressively and forcefully” groped between her legs, the victim told the court in mid-May.

The three most recent assaults, against Australian woman Tonya Lee in 1986, could attract a maximum term of 10 years each.

British barrister Kama Melly says Justice Nigel Sweeney will take into account modern sentencing guidelines even though the offences are, to varying degrees, historic.

“He sentences by today’s attitudes and approach, however he is bound by the maximum sentences that were available (at the time),” the sexual offences specialist told AAP.

Harris is the second person to be convicted under Operation Yewtree, which was set up in the wake of the Jimmy Savile scandal.

Publicist Max Clifford in May was jailed for eight years for indecently assaulting four young women between 1977 and 1984.

He was given consecutive sentences and Ms Melly expects Harris will be too.

“I’m certainly saying it (the overall sentence) will be measured in years rather than months, but I’m not sure it will be as high as Max Clifford.”

The sentence will depend to a large extent “on the psychological harm that’s been done to the victims”, the barrister said.

Ms Lee, who waived her right to anonymity, has already described how the assaults at a London pub almost 30 years ago led to eating disorders and problems with alcohol.

Likewise, Harris’s main victim – a childhood friend of his daughter Bindi – became a teenage alcoholic as a result of being assaulted repeatedly from the age of 13.

She only quit drinking in her mid-30s in 2000 after years of counselling.

The other two victims, including the girl groped near Portsmouth, told the court during Harris’s eight-week trial they still had a physical reaction if they saw the Australian on TV or in a newspaper.

Defence barrister Sonia Woodley QC – back from illness – is expected to make submissions on mitigation regarding Harris’s age and health.

But former detective-turned-investigative journalist Mark Williams-Thomas still thinks the 84-year-old will be jailed for a decade.

Williams-Thomas played a key role in exposing Savile’s crime through his 2012 Exposure documentary.

On Thursday he tweeted a link to the sentencing remarks in the Clifford case with the comment “a useful guidance”.

After Harris was found guilty the respected journalist said the fact one of Harris’s victims was so young was an aggravating factor.

“Yes, he’s an old man, but I expect he’s probably going to receive a sentence somewhere around 10 years,” Williams-Thomas told the ABC.

“He came here as a man who was completely defiant. He didn’t accept any of the charges against him.”

The jury was unanimous when finding the Australian guilty.

Justice Sweeney on Monday made it clear Harris can expect to go to jail.

He’ll begin sentencing at 10am local time (1900 AEST) on Friday.