Free tool · Money
GST calculator NZ
Add 15% GST to a price, or take it out of one that already includes it. The working is shown, so you can check any quote or invoice.
GST calculator 15%
- Excl. GST
- $100.00
- GST (15%)
- $15.00
- Incl. GST
- $115.00
Working: $100.00 × 1.15 = $115.00
The short answerTo add GST in New Zealand, multiply the price by 1.15. To find the GST inside a GST-inclusive price, multiply it by 3 and divide by 23. To get the price before GST, divide the GST-inclusive price by 1.15. New Zealand's GST rate is 15%.
How do I add GST to a price?
Multiply the price before GST by 1.15. That adds the 15% in one step.
- GST only: price × 0.15. On $80, that's $12.
- Price including GST: price × 1.15. $80 becomes $92.
Once you're GST-registered, your quotes and price lists should say whether they're "plus GST" or "GST incl." Business customers usually think in prices before GST, and everyday customers in the price they pay.
How do I remove GST from a price?
To find the GST inside a GST-inclusive price, multiply by 3 and divide by 23. To get the price before GST, divide the inclusive price by 1.15.
Why 3/23? GST is 15/100 of the price before GST. Add the two and the inclusive price is 115/100, so the GST is 15/115 of it, which simplifies to 3/23. It's the number accountants use when they "back out" the GST.
GST examples at 15%
| Excl. GST | GST | Incl. GST |
|---|---|---|
| $20 | $3 | $23 |
| $100 | $15 | $115 |
| $400 | $60 | $460 |
| $1,000 | $150 | $1,150 |
| $60,000 | $9,000 | $69,000 |
What are the common GST mistakes?
- Taking 15% off an inclusive price. $115 less 15% is $97.75, not $100. Use 3/23 to find the GST instead.
- Forgetting to add it once you register. If your prices don't go up, the GST comes out of your own pocket. Kev's mate Pete learned that one the hard way.
- Charging GST before you're registered. You can't. Register first, then charge it.
- Treating GST as income. It's money you're holding for Inland Revenue. Your turnover for the $60,000 GST test doesn't include it either.
Not sure if you need to register at all? Read Do I need to register for GST? Setting prices? Try the margin calculator.
Questions owners ask
How do I calculate 15% GST in NZ?
Multiply the price before GST by 0.15 to get the GST, or by 1.15 to get the GST-inclusive price. So a $200 job is $30 of GST and $230 including GST. Use the calculator above for any amount; it rounds to the nearest cent.
How do I work out the GST in a GST-inclusive price?
Multiply the price by 3, then divide by 23. That's the GST fraction for a 15% rate. A $115 price includes $15 of GST, and a $46 price includes $6. Then take the GST away to get the price before GST, or divide the inclusive price by 1.15, which gives the same answer.
Why can't I just take 15% off a GST-inclusive price?
Because the 15% was added to the smaller, pre-GST price. Taking 15% off $115 gives $97.75, but the real price before GST is $100. The GST share of an inclusive price is 3/23, or about 13.04%, not 15%.
What is the GST rate in New Zealand?
15%. It's been 15% since 1 October 2010. GST started in New Zealand in 1986 at 10% and went up to 12.5% in 1989. One rate covers most goods and services, with a few exempt or zero-rated exceptions.
Is GST charged on everything in New Zealand?
Most things, but not all. Some supplies are exempt, such as residential rent and most financial services, so no GST is charged. Others are zero-rated, such as most exports, so GST is charged at 0%. If you're unsure about a sale, check IRD's guidance or ask your accountant.
Can I charge GST if I'm not registered?
No. Only GST-registered businesses can charge GST, and they then pay it to Inland Revenue. If you're not registered, your prices simply don't include GST. You must register once your turnover reaches $60,000 in 12 months, or you expect it to.
General information, not tax advice. The calculator uses New Zealand's standard 15% rate and rounds to the nearest cent. Check the official sources below or talk to your accountant before you file.
Where's this from?
Checked against these sources on 7 November 2026 by MySMB Editorial. Spotted a mistake? Tell us and we'll fix it.
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