A school bus travels down a slushy-covered road as school resumes following a winter storm on March 15 in Poland. Credit: Robert F. Bukaty / AP

AUGUSTA, Maine — Maine schools will get an unexpected windfall after state officials said a math error led them to overestimate a key figure setting aid to districts.

On net, nearly $42.4 million more in state aid will go to school districts, including $3.6 million in Portland, more than $800,000 in Lewiston and nearly $900,000 in Bangor. No district will get less money, but many will see no increase, according to Maine Department of Education data.

A “duplicative data entry” issue caused the mistake, the department said in a Tuesday notice to districts. A tax figure that helps determine funding allocations was originally set too high, and reducing it means state funding will rise to offset local contributions to schools.

The incorrect calculations date back to January. An education department spokesperson said the mistake would not require changes to the $9.8 billion two-year budget set to pass the Legislature by simple majorities on Thursday. Majority Democrats advanced that plan last week over Republican opposition.

That spending plan will maintain the state’s obligation to pay 55 percent of basic K-12 education costs. While that has been required since a 2004 referendum, it went unmet until Gov. Janet Mills and the Legislature passed a budget in 2021 benefiting from billions of dollars in federal COVID-19 relief.

Michael Shepherd joined the Bangor Daily News in 2015 after three years as a reporter at the Kennebec Journal. A Hallowell native who now lives in Augusta, he graduated from the University of Maine in...