NZ RWT Savings Calculator 2026

Calculate Resident Withholding Tax (RWT) on your savings interest. Compare your selected RWT rate against your marginal tax rate to see if you'll owe a top-up or receive a refund at year-end. Choose the right RWT rate to minimise under/overpayment.

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NZ RWT Savings Calculator 2026 — Resident Withholding Tax on Interest

Free New Zealand RWT (Resident Withholding Tax) calculator for savings interest. Estimate tax deducted at source, top-up or refund due, and net interest after tax.

Interest Income$5,000
RWT Deducted$1,50030% RWT rate selected
Tax at Marginal Rate$1,65033% marginal rate
Top-Up Due$150Additional tax at year-end
Net Interest After Tax$3,350

Resident Withholding Tax (RWT) is deducted by banks and financial institutions from interest you earn on savings, term deposits, and bonds. You can choose your RWT rate (10.5%, 17.5%, 30%, or 33%) by telling your bank. If the RWT rate is lower than your marginal tax rate, you'll owe the difference at year-end. If it's higher, you'll get a refund. Choose 30% to avoid most top-ups unless you're in the 33% or 39% bracket.

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