Reverse GST Calculator for New Zealand
Enter a GST-inclusive price in dollars and get the amount excluding GST and the 15% GST it contains.
Result
Enter an amount to see the result.
For general information only, not tax advice. Some supplies are zero-rated or exempt – check with Inland Revenue if you are unsure.
How to remove GST from a price
GST in New Zealand is 15% of the price before GST, so it makes up 3/23 of a GST-inclusive price.
| Formula | Example: $115 | |
|---|---|---|
| Price excluding GST | total ÷ 1.15 | $115 ÷ 1.15 = $100.00 |
| GST | total × 3 ÷ 23 | $115 × 3 ÷ 23 = $15.00 |
| Check | excluding GST × 15% | $100 × 0.15 = $15.00 |
For a $100 GST-inclusive price, the GST is $100 × 3 ÷ 23 = $13.04, and the price excluding GST is $86.96.
Examples: GST inside common amounts
| Price including GST | Excluding GST | GST (3/23) |
|---|---|---|
| $50 | $43.48 | $6.52 |
| $100 | $86.96 | $13.04 |
| $115 | $100.00 | $15.00 |
| $500 | $434.78 | $65.22 |
| $1,150 | $1,000.00 | $150.00 |
Amounts are rounded to the nearest cent. The calculator works out the price excluding GST first and then subtracts it from the total, so the two always add back to the amount you entered.
GST rates in New Zealand
| Rate | Applies to |
|---|---|
| 15% | Most goods and services |
| 0% | Zero-rated supplies, such as exported goods |
Exempt supplies also have no GST in the price, but they are not the same as zero-rated supplies and are treated differently on a GST return.
Sources: Inland Revenue – GST and Inland Revenue – Charging GST.
Frequently asked questions
How do I calculate GST from a GST-inclusive price in NZ?
Multiply the price by 3 and divide by 23. In a $115 price the GST is $115 × 3 ÷ 23 = $15, and the price excluding GST is $100. Inland Revenue describes this as taking 3/23 of the GST-inclusive amount.
How do I remove GST from a total?
Divide the total by 1.15. $115 ÷ 1.15 = $100 excluding GST. Then subtract to get the GST: $115 − $100 = $15.
Why is the GST fraction 3/23 and not 15%?
Because GST is 15% of the price before GST. A GST-inclusive price is 115% of that, and 15 ÷ 115 simplifies to 3/23, about 13.04%. Taking 15% off the total over-states the GST: on $115 it gives $17.25 instead of $15.
What does zero-rated mean?
A zero-rated supply is charged GST at 0%, so the price contains no GST. Exports of goods are a common example. Choose the zero-rated option in the calculator for these.
When do I have to register for GST in New Zealand?
When your sales from a taxable activity were at least $60,000 in the last 12 months, or you expect them to be at least $60,000 in the next 12 months. You can also register voluntarily below that amount.