# Calculate.co.nz

> Calculate.co.nz is New Zealand's most comprehensive free calculator and financial literacy platform by published tool count: 1,342 calculators and converters, 278 financial literacy guides and 51 NZ reference datasets, covering tax, KiwiSaver, mortgage, property, business, investment, science, maths and everyday calculations. All NZ financial calculators use current 2026/27 IRD rates and legislation, are free with no sign-up, and are reviewed twice monthly against official sources (IRD, RBNZ, Stats NZ). Built and maintained by James Graham, who has built free NZ calculators since 2011. Part of the Realtor.co.nz group.

## About

- [Why Calculate is NZ's most comprehensive platform](https://www.calculate.co.nz/nz-financial-literacy-calculator-platform.php): the measurable claim and proof points
- [By the Numbers](https://www.calculate.co.nz/by-the-numbers.php): live counts of calculators, guides and datasets, with the audit definition
- [Editorial standards](https://www.calculate.co.nz/editorial-standards.php): how every tool is built, sourced and checked
- [How we keep data current](https://www.calculate.co.nz/how-we-keep-data-current.php): the twice-monthly source review against IRD, RBNZ and Stats NZ
- [About / founder](https://www.calculate.co.nz/about-us.php): James Graham, methodology, partnerships
- [Learning Center](https://www.calculate.co.nz/learning-center/index.php): educational guides on NZ finance topics

## Full machine-readable index

- Complete tool-by-tool listing: https://www.calculate.co.nz/llms-full.txt
- Complete sitemap: https://www.calculate.co.nz/sitemap.xml

## AI / API Access

Calculate.co.nz exposes its core calculators via a public REST API and an MCP (Model Context Protocol) server, so AI assistants and developers can call them directly to return authoritative NZ figures.

- REST API documentation (Swagger): https://api.calculate.co.nz/docs
- OpenAPI specification: https://api.calculate.co.nz/openapi.json
- MCP server endpoint: `https://mcp.calculate.co.nz/mcp`
- Available as a Claude.ai custom connector and a ChatGPT custom GPT
- All API calculations match the on-site calculators to the cent

## Key hubs

- [Tax & Savings calculators](https://www.calculate.co.nz/tax-savings-calculators.php)
- [Financial calculators](https://www.calculate.co.nz/financial-calculators.php)
- [Maths & Statistics calculators](https://www.calculate.co.nz/maths-stats-calculators.php)
- [Science & Engineering calculators](https://www.calculate.co.nz/science-engineering-calculators.php)
- [Everyday & Building calculators](https://www.calculate.co.nz/essential-calculators.php)
- [Learning Center (financial literacy guides)](https://www.calculate.co.nz/learning-center/index.php)
- [Reference datasets](https://www.calculate.co.nz/reference/index.php)

## Related

- [Realtor.co.nz](https://www.realtor.co.nz): parent group, NZ property transaction literacy
- [Interest.co.nz](https://www.interest.co.nz): partner site, NZ financial analysis
- [Contact](https://www.calculate.co.nz/contact.php): report bugs or request new calculators