GST Calculator NZ: Add or Take Off 15%
To find the goods and services tax (GST) in a price, multiply by 3 and divide by 23. Add GST with × 1.15. Built for NZ small-business owners as a planning calculator, not accounting advice.
Take GST out with × 3 ÷ 23
A $230 price includes $30.00 GST. The price before GST is $200. Adding 15% to $200 gives $230.
GST means goods and services tax. This tool uses the New Zealand rate of 15%. It does not handle special supplies or adjustments.
Worked example: a cafe
All sales and eligible costs in this example include 15% GST. The payments-basis cafe received $46,000 and paid $17,250 in September and October 2026. Keep $3,750.00 for the return. It is due 30 November 2026 because 28 November is a Saturday.
Check your return date
A period ending 31 March is normally due 7 May. A period ending 30 November is normally due 15 January. Other periods are normally due on the following month’s 28th. Weekend or national public holiday dates move to the next working day. Confirm in myIR.
Rules and sources checked 4 November 2026. Read the linked GST guide for IRD sources, eligible costs and help.