Hopes proposed child support changes will help accurately calculate how much it costs to raise a child.

The Government's IRD overhaul would see child support payments come straight out of parents' salaries and wages.

But Child Support NZ founder Rob St George told Nadine Higgins there are other things that need fixing in the system first.

"I have some parents that get as little as $60-70 a month for their child and others, on the other end of the spectrum that pay up to $1600 for one child."

The proposed changes to child support would separate out the money aspect from a messy relationship breakup.

Mr St George told Nadine Higgins it'll mean payments are one less thing for guardians to worry about.

"It's certainly going to help some people with their financial planning, especially if their income changes during the year."

Mr St George said it's unfair payments are based on income, and not on what kids actually cost.

LISTEN ABOVE TO CHILD SUPPORT NZ FOUNDER ROB ST GEORGE SPEAK TO NADINE HIGGINS ON EARLY EDITION