The Official Cash Rate has been cut to 4.75%.
The Reserve Bank's lowered it by 50-basis points from 5.25% in a move predicted by economists.
The bank says inflation's within its 1-3% target range and is converging on the 2% midpoint.
It says economic activity is subdued, with weak business investment and consumer spending.
Herald business editor at large Liam Dann told Matt Heath and Tyler Adams it's good news for borrowers.
He says it's money in the pocket for mortgage holders and for businesses struggling with high debt.
Banks have already begun cutting their home loan and lending rates.
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