Comparison methodology

So that our platform comparison reads as evidence rather than marketing, here is exactly how it is made.

What we compare on

We use dimensions that anyone can verify by visiting the sites, rather than subjective judgements of quality:

• Primary focus of each platform, described in neutral terms.
• NZ-specificity: whether the tools are built for New Zealand rules.
• Breadth: the range of calculator categories offered.
• Learning support: whether calculators are paired with explanatory guides.
• Access: free to use, and whether sign-up is required.
• Reference data: maintained NZ rates and figures.
• Machine and AI access: a public API or similar.
• Update process: a stated approach to keeping data current.

What we deliberately do not do

• No contestable head-counts for other sites. We publish our own audited tool count, but we do not assert a specific number of calculators for competitors, because those numbers are hard to verify and change. We describe their focus instead.
• No subjective "we are better" claims. Where Calculate leads, it is on a countable, checkable dimension.
• No disparagement. Each platform is described by its genuine strengths.

Sources

Our own figures come from the audited By the Numbers count. Descriptions of other platforms are based on their publicly visible features at the date of review. New Zealand consumer law requires comparative claims to be substantiable, which is why the comparison stays on observable features and our own verifiable numbers.

Keeping it fair and current

Platforms change. The comparison carries a review date, and if you believe anything is inaccurate or out of date, please tell us and we will check and correct it. This reflects the same approach we take to keeping our own data current.

Last reviewed 2026-06-02. Maintained by James Graham.