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Effective Marginal Tax Rate Calculator

See your true effective marginal tax rate — PAYE, ACC, student loan, Working for Families and Best Start abatements stacked. Often 50-90% for NZ middle earners.

By Konstantin IakovlevPublished 28 March 2026Last reviewed
Data stays on your deviceIRD sourced data

About this calculator

This calculator implements Treasury TAWA effective marginal tax rate methodology from NZ Treasury (TAWA) + IRD. Last consulted 18 May 2026. Verify the figures yourself by following the link.

NZ EMTR components (FY 2026-27)

Each abatement stacks on the same gross income
  • •PAYE top bracket: 39% above $180k
  • •ACC earner's levy: 1.75% up to $156,641
  • •Student loan rate: 12% above $24,128/yr
  • •WfF abatement rate: 27¢ per $1 above $42,700
  • •Best Start abatement (Y2-3): 21¢ per $1 above $79k
  • •Worst-case EMTR (NZ): ~90% (parent on $80-90k)

Source: NZ Treasury — TAWA Model

Disclaimer

This calculator provides estimates for general information purposes only. Results should not be relied upon as professional financial, tax, or legal advice. Tax rates and thresholds are based on publicly available IRD data and may change. Always consult a qualified tax agent or financial adviser for advice specific to your circumstances.

How NZ Effective Marginal Tax Rate (EMTR) stacks

Multiple income-tested levies and abatements all hit the same gross income, producing the EMTR.

  1. 1

    PAYE marginal rate

    PAYE_marginal = bracket(annual_income) — 10.5/17.5/30/33/39%

    Top bracket 39% above $180,000.

  2. 2

    ACC earner's levy

    ACC = 1.75% on first $156,641

    Caps out at the liable earnings ceiling.

  3. 3

    Student loan deduction

    SL = 12% on income above $24,128

    Add 12 percentage points if you have a student loan.

  4. 4

    Working for Families abatement

    WfF_abate = 27¢ per $1 above $42,700 family income

    Effectively another 27% tax on this income range.

  5. 5

    Sum to EMTR

    EMTR = PAYE + ACC + SL + WfF_abate + Best_Start_abate

    Can hit 50-90% for middle-earning families.

Worked example

Inputs: $70,000 family income with student loan, 2 kids on WfF

Result: PAYE 30% + ACC 1.75% + SL 12% + WfF 27% = 70.75% EMTR. Of next $100, keep $29.25.

Frequently Asked Questions

What is the Effective Marginal Tax Rate (EMTR)?
EMTR is the true percentage of your next dollar of income that disappears through tax and benefit abatement. In NZ, EMTRs of 50–90% are common for middle earners with kids — because PAYE, ACC, student loan (12%), Working for Families abatement (27c per $1), and Best Start abatement (21c per $1) all stack on the same income. Treasury's TAWA model is the canonical source. Source: NZ Treasury.
How can I reduce my EMTR?
The main lever is salary sacrifice into KiwiSaver — voluntary contributions above 3% reduce your assessable income for WfF abatement purposes (but not PAYE). For couples, income-splitting via a sole-trader structure or family trust may help (with professional advice). Pre-tax deductions like income protection or work-related expenses also count. Source: IRD.

How this calculator works

This effective marginal tax rate calculator uses the latest data from official New Zealand government sources to provide accurate results. All calculations are performed in your browser — your data never leaves your device.

All calculations are performed in your browser — your data never leaves your device. Results are for general guidance only and should not be considered professional financial advice.

Built and maintained by Konstantin Iakovlev. Data sourced from the IRD and official New Zealand government sources.

Last reviewed:

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