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New Zealand GST Calculator

Add GST to a price, or work out how much GST is included in a GST-inclusive amount. The calculator uses New Zealand’s 15% GST rate by default and shows the working so you can check it.

Does your amount include GST?
NZ$
%

NZ standard rate: 15%

Results update as you type.

Results

Total including GST

$115.00

Amount excluding GST (you entered)
$100.00
GST at 15%
$15.00
Total including GST
$115.00
Arithmetic only — not tax advice. Check current Inland Revenue guidance before relying on results.

How GST is calculated

Adding GST — when your price excludes GST:

GST   = amount_excl_GST × rate
total = amount_excl_GST × (1 + rate)
Rate as a decimal: 15% = 0.15

Removing GST — when your price already includes GST:

amount_excl_GST = amount_incl_GST ÷ (1 + rate)
GST             = amount_incl_GST − amount_excl_GST

At 15%, the GST inside an inclusive price is exactly 3/23 of it, a handy shortcut for mental maths.

Examples at 15%

You haveExcl. GSTGSTIncl. GST
A NZ$80 service fee before GST$80.00$12.00$92.00
A NZ$1,000 quote before GST$1,000.00$150.00$1,150.00
A NZ$57.50 receipt including GST$50.00$7.50$57.50
A NZ$99.99 GST-inclusive price$86.95$13.04$99.99

Does my amount include GST?

Prices shown to consumers in New Zealand generally include GST. Quotes between businesses are often given “+ GST”. If a document says “GST inclusive” or “incl. GST”, use Remove GST; if it says “excl. GST” or “+ GST”, use Add GST. If you are unsure, ask the supplier.

Limitations

  • This tool does arithmetic only. It doesn’t decide whether a supply is taxable, zero-rated or exempt, or whether you need to register — that depends on your circumstances.
  • The default 15% reflects Inland Revenue guidance when we checked. Confirm the current rate before using results for tax.
  • It is not tax advice. For your situation, check Inland Revenue or talk to a tax adviser.

Charging customers by card? Combine this with the Stripe fee calculator to see what you keep after fees.

Frequently asked questions

What is the GST rate in New Zealand?

Inland Revenue states that GST is charged at 15%. This calculator uses 15% by default. You can change the rate if you need to model a different figure.

How do I calculate GST from a GST-inclusive price?

Divide the inclusive price by 1.15 to get the GST-exclusive amount, then subtract that from the inclusive price. At 15%, that is the same as multiplying the inclusive price by 3 and dividing by 23. For example, NZ$230 includes NZ$30 GST.

Why isn’t GST on an inclusive price just 15% of the total?

Because the 15% applies to the price before GST, not to the total. 15% of NZ$115 is NZ$17.25, but the GST in NZ$115 is NZ$15 — the GST was 15% of the NZ$100 base.

When do I have to register for GST?

Inland Revenue says you must register if your turnover from a taxable activity was at least NZ$60,000 in the last 12 months, or is expected to reach NZ$60,000 in the next 12 months. You can choose to register below that. Check Inland Revenue for your situation.

Should I round GST per item or on the invoice total?

This calculator rounds each result to the cent. On invoices with many lines, rounding per line and rounding the total can differ by a cent or two. Follow the approach your accounting software and Inland Revenue guidance support.

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