Spending data comes from NZ Treasury's Budget 2026 expenditure dataset (published 28 May 2026): Main Estimates for every Vote and appropriation for the year ending 30 June 2027, totalling $200,413,181,000 across 51 Votes. This excludes one item: a $32.2 billion non-cash transfer of existing school property assets from the Ministry of Education to the new New Zealand School Property Agency (the Estimates total including it is $232,648,181,000). It moves assets between Crown bodies rather than spending tax, so including it would make Education look more than 2.5 times larger. New Zealand Superannuation is shown separately for readability, carved from Social Development; this does not change the total or make it a separate legal Vote. Vote colours follow Treasury's functional classification. 48 Votes can be expanded to their biggest appropriations; 3 are shown as single lines.
Income tax is allocated across Votes in proportion to each Vote's share of Budget 2026 spending. This reflects the fact that tax and borrowing are pooled before spending, rather than tracing individual tax dollars. The ACC earner's levy is shown separately because it funds the ACC scheme, not Government Votes.
The treemap groups the 32 smallest Votes (each under about 0.6% of total spending) into “Smaller Votes”; all are still listed below. New Zealand Superannuation stays visible because it is a major Social Development appropriation. KiwiSaver goes to your retirement account and student loan repayments go to your loan, so neither is government spending.
The tax-flow diagram uses tax revenue by type from the Budget 2026 revenue dataset (Main Estimates, year ending 30 June 2027). “Personal income tax” is source deductions, other persons and fringe benefit tax; “Other taxes” includes withholding taxes, customs and excise duties, road user charges and gaming duties. GST is Inland Revenue's GST line only, because the separate Customs GST line would double count it. The total ($134.3 billion) is within about 1% of Treasury's Budget 2026 forecast core Crown tax revenue of $133.0 billion. “Borrowing & other income” is a balancing figure (Vote spending less tax), so it is approximate and includes non-tax income such as fees, dividends and interest. ACC levies fund the separate ACC scheme and bypass Votes; because ACC is not in the Budget datasets, that figure is Treasury's 2025/26 forecast from the Interim Financial Statements of the Government of New Zealand (nine months ended 31 March 2026).
This website was built by a high school maths teacher in his spare time to help his students learn more about how tax actually works in New Zealand today. This means it's not perfect. It's certainly not financial or tax advice. It does not account for tax credits, Working for Families, secondary tax-code quirks or other individual circumstances. If you're a nerd reading this and want to chat more about the spreadsheets behind how tax is calculated, please get in contact. I'm always happy to nerd out about numbers.