Financial Glossary

Marginal Tax Rate

The marginal tax rate is the tax rate applied to the last dollar of income earned. In a progressive tax system, income is taxed in brackets at increasing rates. Your marginal tax rate is the rate of the highest bracket your income reaches, and it only applies to the portion of income within that bracket, not your entire income.

Example

For 2025-2026, a single filer earning $75,000 falls into the 22% marginal tax bracket. However, only income above $47,150 is taxed at 22%. The first $11,600 is taxed at 10%, and income from $11,601 to $47,150 is taxed at 12%. The overall effective tax rate is lower than 22%.

Frequently Asked Questions

Does my marginal tax rate apply to all my income?

No. In a progressive tax system, only the portion of income within each bracket is taxed at that bracket's rate. Your entire income is not taxed at your marginal rate. This is a common misconception.

How does knowing my marginal tax rate help?

Knowing your marginal rate helps with financial planning decisions, such as whether to work overtime (you know what portion of extra income goes to taxes), contribute to retirement accounts (tax savings at your marginal rate), or realize capital gains.

Related Resources

Tax Calculator Salary Calculator Tax Brackets by Country All Glossary Terms

Official Sources

New Zealand calculators use data from the following official government agencies:

Inland Revenue (IRD) — Income tax brackets, KiwiSaver rules, and ACC levies.
Stats NZ — Wage data, employment statistics, and cost of living indices.
Reserve Bank of New Zealand (RBNZ) — Official cash rate and monetary policy data.

Methodology

Our New Zealand calculators follow tax brackets, KiwiSaver contribution rates, and ACC levies published by Inland Revenue (IRD). Economic data is sourced from Stats NZ. Mortgage calculations use RBNZ official cash rate and market averages. All figures are for educational purposes.

Data Sources

All tax brackets, contribution rates, and economic data used in our calculators are sourced from the official government publications listed above. Rates are updated at least annually to reflect the latest tax year and regulatory changes. Users should verify critical figures with official sources or qualified professionals.

Last updated: June 2026. Information may change; always verify with official sources.

Last Updated: June 2026 — Reviewed Against Official Sources