Spector, 69, was found guilty of second-degree murder in the shooting death of Clarkson at his Los Angeles area home. His lawyers, who argued the woman's death was a suicide, have vowed to appeal the conviction.
"All our plans together are destroyed. Now I can only visit her in the cemetery," the Los Angeles Times quoted Lana's mother Donna as saying before Friday's sentencing.
The Times Thursday said the guilty verdict carries a mandatory sentence of 15 years to life in prison, and it was up to the judge sentencing Spector to decide how many more years to add to the minimum sentence for the use of a firearm.
The newspaper said prosecutors asked that four more years be added, while Spector's legal team pushed for three.
Friday's sentencing means Spector will first be eligible for parole at age 88.