He also raised $812 for the KidsCan charity through the Givealittle website, because he wanted to help out kids that didn't have as much as he did.
Jimi said he liked the way short and spiky hair felt, and lots of kids at school had told him it looked cool.
He had hoped to raise $200 for KidsCan so he was really excited about raising more than four times that amount.
His mother Kolet Vermeulen said Jimi decided a few weeks ago that he wanted to have short hair.
His class was discussing fundraising and thinking about other people at the time, so it seemed like it would be a really cool thing to do, Ms Vermeulen said.
"Jimi's really into helping other kids," she said.
"People gave him cash in the weekend, and instead of saying 'yipee, money for Lego' like most kids would, he brought it to me and said, 'look mum, more money for charity'."
KidsCan was a logical choice of charity to raise money for, she said.
"We often talk with Jimi about how lucky he is, and how other kids don't have as much as he does," she said.
"He could have raised money for a kids cancer foundation, but we decided to raise money for kids from families with financial difficulties instead."
KidsCan will send Jimi a special certificate with how much he has raised.
"It will show Jimi if you do good, you'll receive good," Ms Vermeulen said.
She said she was considering shaving her hair off for charity too.