Know where the numbers come from

Sources & calculation methodology

Rate review: 25 September 2026. Supported year: 1 April 2026 to 31 March 2027. Independent planning estimates, not an Inland Revenue service.

Salary calculation

Gross earnings are annualised using the selected period. Monthly × 12, four-weekly × 13, fortnightly × 26 and weekly × 52. Hourly and daily conversions use the working pattern entered or the stated defaults. Income tax is calculated progressively, then eligible IETC is deducted. ACC, employee KiwiSaver and any main-job student loan estimate are deducted from gross earnings.

Rules used

Income tax: 10.5%, 17.5%, 30%, 33%, 39%, at thresholds $15,600 / $53,500 / $78,100 / $180,000.
ACC: 1.75% up to earnings of $156,641. Employee salary/wages only.
Student loan: 12% above $24,128, annualised one-main-job estimate.
IETC: optional full-year estimate, up to $520, abating at 13% above $66,000 to zero at $70,000. Eligibility must be confirmed.
KiwiSaver: selected employee rate × gross earnings. Employer contributions, ESCT and government contributions excluded.
GST: standard 15%; remove included GST using 3/23.

Official source links

Rounding and limitations

We retain precision while calculating and round displayed currency to two decimals. Annual estimates divided by periods are not a pay-period payroll engine. Irregular lump sums, second jobs, tailored codes, overseas borrowers, self-employed ACC and partial-year eligibility are outside scope. The overtime calculator compares annual estimates; it does not calculate an employer’s special lump-sum withholding.

Savings and loans

Savings compound monthly with end-of-month deposits, before tax and fees. Loan repayment uses the standard fixed-rate amortisation formula. Rates are user inputs, not current lending offers.