The extra time in jail did little to satisfy throngs of angry people who gathered outside the courthouse, convinced of her guilt.
But it could provide time for the public furor over her acquittal to ease somewhat and give Anthony's attorneys a chance to plan for her safety.
Two days after the verdicts, most of the jury remained silent, with their names kept secret by the court. One juror said that the panel agreed to acquit Anthony because prosecutors had not shown what happened to the toddler.
When she is released, Anthony, 25, must decide whether to return to a community in which many onlookers long ago concluded that she's a killer, or to a home strained by her defense attorneys' accusations of sexual abuse.
Judge Belvin Perry gave her the maximum sentence of four years for four convictions of lying to authorities. He denied a defense request to combine the misdemeanor counts, which could have made her eligible for immediate release.
"As a result of those four specific, distinct lies, law enforcement expended great time and resources looking for Caylee Marie Anthony," the judge said.
With time served and credit for good behavior, she is eligible for release.
Outside the courthouse, a cluster of protesters chanted "Justice for Caylee" as they waved signs that said "Arrest the Jury!!" and "Jurors 1-12 Guilty of Murder." One man had duct tape with a heart-shaped sticker over his mouth, similar to the way prosecutors contend Caylee died. Increased police presence included officers on horseback.
"At least she won't get to pop the champagne cork tonight," said Flora Reece, an Orlando real-estate broker who stood outside the courthouse holding a sign that read "Arrest the Jury."
Prosecutors and defense attorneys did not comment.
Anger continued to spread online, with commenters vilifying Anthony on social-media networks. Nearly 22,000 people "liked" the "I hate Casey Anthony" page on Facebook, which included comments wishing her the same fate that befell Caylee.
The potential for Anthony to profit off the case was infuriating to many who said they feared that she could become rich by selling her story to publishers or filmmakers, or by signing a lucrative television contract.