NZ GST Calculator

Add or remove 15% GST in a click

Amount (excl. GST)

GST rate

Amount excl. GST $0.00

GST amount $0.00

Total incl. GST $0.00

Standard NZ GST rate is 15%. This tool is for guidance only — check ird.govt.nz for official rules.

NZ GST Calculator

Calculate New Zealand GST (Goods and Services Tax) instantly. Add 15% GST to GST-exclusive prices or remove GST from GST-inclusive totals using our free online NZ GST Calculator.

Whether you're a business owner, freelancer, accountant, contractor, or shopper, this calculator helps you determine GST amounts accurately in seconds.

What Is GST in New Zealand?

GST (Goods and Services Tax) is a 15% consumption tax charged on most goods and services sold in New Zealand.

Businesses registered for GST collect this tax from customers and pay it to New Zealand's Inland Revenue Department (IRD).

GST was introduced in 1986 and has been 15% since 1 October 2010.

Who Can Use This NZ GST Calculator?

This calculator is useful for:

Small business owners
Accountants
Freelancers
Self-employed professionals
Contractors
Retailers
Online sellers
Customers checking receipts
Students learning GST calculations

How to Use the NZ GST Calculator

To Add GST

Select Add GST.
Enter the price excluding GST.
Choose the GST rate.
The calculator instantly displays:
- GST amount
- Total including GST

To Remove GST

Select Remove GST.
Enter the GST-inclusive amount.
Choose the GST rate.
The calculator automatically shows:
- Original price before GST
- GST portion

How GST Works in New Zealand

GST is collected whenever taxable goods or services are sold.

Businesses charge GST on behalf of the government and later pay the collected GST to the Inland Revenue Department (IRD).

The standard GST rate is 15%.

Older invoices created before 1 October 2010 may use the historical 12.5% rate.

Adding GST

If you know the price before GST and want the final selling price:

Formula

GST = Amount × 15%

Total = Amount + GST

or

Total = Amount × 1.15

Example

Original price:

$100

GST:

100 × 15%

= $15

Final price:

$115

Removing GST

If you already have the total price and want to find the original amount before GST:

Formula

Original Amount = Total ÷ 1.15

GST = Total − Original Amount

Example

Receipt Total:

$115

Original price:

115 ÷ 1.15

= $100

GST:

115 − 100

= $15

Why You Cannot Simply Subtract 15%

One of the most common mistakes is subtracting 15% directly from the total amount.

For example:

$115 × 15%

= $17.25

Subtracting this gives:

$97.75

This is incorrect.

The GST was originally calculated from $100, not from $115.

To reverse GST correctly, divide the GST-inclusive total by 1.15.

GST Formula Cheat Sheet

Calculation	Formula
Add GST	Amount × 1.15
Remove GST	Total ÷ 1.15
GST Amount	Amount × 0.15
GST From Total	Total − (Total ÷ 1.15)

GST Calculation Examples

Example 1

Amount excluding GST:

$50

GST:

$7.50

Total:

$57.50

Example 2

Invoice Total:

$230

Original Amount:

230 ÷ 1.15

= $200

GST:

$30

Example 3

Price:

$999

GST:

$149.85

Total:

$1,148.85

Historical GST Rates in New Zealand

Period	GST Rate
Before July 1989	10%
July 1989 – September 2010	12.5%
Since 1 October 2010	15%

The calculator includes the historical 12.5% GST option for working with older invoices and financial records.

Benefits of Using Our NZ GST Calculator

Instant GST calculations
Supports adding and removing GST
Accurate results
Mobile friendly
No registration required
Free to use
Suitable for businesses and individuals
Includes historical GST rates

Common GST Mistakes

Avoid these common errors:

Subtracting 15% directly from the total
Using the wrong GST rate
Forgetting to include GST on taxable sales
Mixing GST-inclusive and GST-exclusive prices
Rounding incorrectly

Frequently Asked Questions

What is the GST rate in New Zealand?

The current standard GST rate is 15%.

How do I calculate GST?

Multiply the GST-exclusive amount by 15%, or multiply by 1.15 to get the GST-inclusive total.

How do I remove GST?

Divide the GST-inclusive amount by 1.15.

Why divide by 1.15?

Because the GST has already been added to the original price. Dividing reverses the calculation accurately.

Is GST included in advertised prices?

For most consumer sales, prices displayed are GST-inclusive.

Can I use this calculator for invoices?

Yes. It works for invoices, receipts, quotations, and estimates.

Does this calculator support the old 12.5% GST?

Yes. Historical GST calculations are supported.

Is this calculator free?

Yes. It is completely free with no signup required.

Conclusion

Our NZ GST Calculator makes it easy to add or remove GST from any amount in seconds. Whether you're preparing invoices, checking receipts, calculating prices, or reviewing historical records, this tool provides fast and accurate results using New Zealand's GST rules.

For historical transactions, you can also calculate using the previous 12.5% GST rate.

Disclaimer: This calculator provides general guidance only and does not constitute tax advice. For official GST rules and obligations, refer to New Zealand's Inland Revenue Department (IRD).