How much GST do I add in New Zealand?

GST in New Zealand is 15%. To add GST to a price, multiply by 1.15: a $100 item becomes $115, with $15 of GST. To find the GST already inside a GST-inclusive price, multiply by 3 and divide by 23: a $115 total contains $15 of GST.

The 3/23 method works because the $15 of GST is 3/23 of the $115 inclusive total. It is the correct way to back out GST from a tax-inclusive figure.

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Indicative only, not financial advice. Uses current New Zealand rates for 2026/27. Last reviewed 2026-06-02. See also financial literacy NZ.

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