"No school, early learning service or nga kohanga reo will see a reduction in their funding as a direct result of this change.
"In fact, we expect some will gain significantly."
Dave Randall, principal of Tauranga's biggest high school Otumoetai College (decile 7), said it was "about time" the "archaic" decile system was replaced.
He said low decile schools faced an unfair stigma that was based on their neighbourhood rather than their learning and teaching performance.
"There are some very low decile schools out there doing an amazing job."
The ministry's promise that no schools would lose funding would buy them some goodwill as they worked out the details, he said.
He was interested to know how the ministry would gather the data the new assessment would be based on.
Richard Inder, principal of decile 2 Gate Pa School, said he believed most principals favoured the concept of change.
"But the devil will be in the details."
"I am pleased to know the ministry has said that no schools will lose funding," Mr Inder said.
Both principals hoped the new system would increase their schools' operational funding.
Former Education Minister Hekia Parata has previously said a statistical "risk" index can target funding in a more "fine-grained way" by estimating for each student how at risk of educational underachievement they are.
It uses a range of indicators relating to each child, including how old the mother was at their birth, how many siblings the child has, parental income, father's offending history, and the child's ethnicity.
Additional reporting - Nicholas Jones