GST Calculator NZ: Add or Remove 15% GST Instantly
Use our Nz GST calculator to calculate Goods and Services Tax (GST) in New Zealand quickly and accurately. Instantly add or remove the 15% GST, calculate GST inclusive and GST exclusive prices, determine the GST amount and estimate the total invoice value for businesses, freelancers, contractors, retailers and consumers.
GST Calculator NZ
Add or remove 15% GST instantly — plus a multi-item invoice builder for business use. Based on current IRD rates.
| Description | Amount (excl. GST) | |
|---|---|---|
Add GST
How To Calculate GST With NZ GST Calculator?
Choose the option Add GST if you have a price before tax or Remove GST if you have a total price that already includes tax. Enter your amount, confirm the tax rate 15% standard, by default, and your excl. GST, GST, and incl. GST figures update instantly. For invoices with several items, use the Multi Item Invoice Builder below to get a combined subtotal, GST and grand total. Download Your GST results by click the the download button to download Your GST results.
Remove GST
The GST Formulas Used In – Add, Remove, Extract
Add GST to a net price
Amount × 1.15
Worked example ($100 / $115)
$100 × 1.15 = $115.00
Remove GST from a gross price
Amount ÷ 1.15
Worked example ($100 / $115)
$115 ÷ 1.15 = $100.00
Extract GST portion from a gross price
Amount × 3 ÷ 23
Worked example ($100 / $115)
$115 × 3 ÷ 23 = $15.00
Why 3/23? When GST is 15%, the tax component of a GST-inclusive price is always 3/23 of the total, because 15 ÷ 115 simplifies to 3/23. This shortcut is the exact method IRD-aligned tools and accountants use to pull GST out of a total without a separate subtraction step.
What Is GST in New Zealand?
GST (Goods and Services Tax) is a broad-based consumption tax applied to most goods and services sold in New Zealand, currently set at a flat 15%. GST introduced in 1986 at 10%, it was raised to 12.5% in 1989 and to its current 15% on 1 October 2010. Unlike many countries, New Zealand applies almost no reduced rates or food exemptions. Use our GST calculator nz for Quick GST Calculations.
| Period | GST rate |
|---|---|
| 1 October 1986 – 30 June 1989 | 10% |
| 1 July 1989 – 30 September 2010 | 12.5% |
| 1 October 2010 – present | 15% |
When Do I Need to Register for GST?
You must register for GST once your taxable supplies exceed $60,000 in any rolling 12-month period, or if you reasonably expect to exceed that threshold in the next 12 months. Registration below that threshold is optional — common among freelancers and exporters who want to claim back GST on business costs even before they’re required to register.
GST Filing Frequency and Deadlines
| Filing frequency | Who it’s for | Typical deadline |
|---|---|---|
| Monthly | Businesses with turnover over $24 million (or by choice) | 28th of the following month |
| Two-monthly | Most small-to-medium businesses (the default) | 28th of the month after each two-month period |
| Six-monthly | Small businesses with turnover under $500,000 (by election) | 28th of the month after each six-month period |
Two well-known exceptions to the standard 28th deadline: the return covering 31 March is due 7 May, and the return covering 30 November is due 15 January, both accounting for holiday-period processing.
Real-World Example — Small Business Invoice
A Wellington design freelancer bills a client $850 for a project, quoted as GST-exclusive. GST at 15% adds $127.50, for a total invoice of $977.50. If the same freelancer instead needs to figure out how much GST was embedded in a $977.50 payment already received, they’d use the extraction formula: $977.50 × 3 ÷ 23 = $127.50 — arriving at the identical figure, confirming the two directions are mathematically consistent. With help of GST calculator all these calculations become easy.
| Step | Calculation | Result |
|---|---|---|
| Net invoice amount | — | $850.00 |
| GST (15%) | $850 × 0.15 | $127.50 |
| Total invoice | $850 + $127.50 | $977.50 |
| GST extracted from total (check) | $977.50 × 3 ÷ 23 | $127.50 ✓ |
Why GST Matters
GST affects nearly every purchase and business transaction in New Zealand. Understanding how GST-inclusive and GST-exclusive pricing works helps businesses comply with IRD requirements, prepare accurate invoices, manage cash flow, claim GST input tax credits, and calculate the correct amount of tax payable with NZ GST calculator.
Related calculators
Access our other New Zealand financial tools to simplify payroll, tax, salary and business calculations.
NZ Paye Calculator
estimate your PAYE tax, take-home pay, KiwiSaver contributions, ACC levy, and net salary using the latest New Zealand tax rates
Hourly to Salary Calculator
Convert an hourly wage to an annual salary or check what a yearly salary works out to per hour, then see the after-tax figure.
Student Loan Calculator
Add a brief description to youWork out your annual student loan repayment above the $24,128 threshold, and how long it’ll take to clear a balance.r card.
KiwiSaver Calculator
See how much you and your employer contribute at each KiwiSaver rate, from 3% to 10%.