NZ GST Return Calculator

This NZ GST return calculator provides a simple arithmetic estimate of GST collected on taxable sales, GST included in eligible business purchases, and the resulting net amount. It does not determine whether individual transactions qualify for a GST claim.

Taxable sales excluding GST (NZD)
Business purchases excluding GST (NZD)

How the estimate works

The calculator applies the standard 15% rate to the GST-exclusive sales and purchase amounts you enter. It subtracts the entered purchase GST from the entered sales GST to produce a simple arithmetic estimate.

Important limitation

A GST return is not just a multiplication exercise. GST treatment can depend on the transaction, taxable supply information, adjustments, zero-rated supplies, exempt supplies and other rules. This calculator should not be used as a filing or tax-position decision tool.

Official source

Inland Revenue: GST

Worked example

If taxable sales are NZ$10,000 and entered business purchases are NZ$4,000, GST on sales is NZ$1,500 and GST on the entered purchases is NZ$600. The simple arithmetic estimate is NZ$900.

Worked example: a cafe’s two-monthly return

A cafe in Dunedin files two-monthly. For the period, its taxable sales are $46,000 excluding GST and its business purchases are $18,400 excluding GST.

GST on sales: $46,000 x 15% = $6,900. GST on purchases: $18,400 x 15% = $2,760. Net GST payable: $6,900 – $2,760 = $4,140. The cafe files its return and pays $4,140 by the due date.

The reverse can happen too. A startup with $5,000 of sales (GST $750) and $23,000 of equipment purchases (GST $3,450) ends up with a net refund of $2,700, which IRD pays after the return is processed.

Getting your figures ready

Before you use the estimate, gather the period’s taxable sales excluding GST and the business purchases you can support with proper tax invoices or taxable supply information. Leave out private spending and anything you are unsure about, and note any adjustments for change in use or bad debts. Then check the due date for your period and file through myIR.

Why this is only an estimate

Actual GST reporting can involve GST-free or zero-rated supplies, exempt supplies, adjustments, private use, accounting basis, tax invoices and other rules. This tool does not determine whether a particular purchase creates an input tax credit.

Frequently asked questions

Can this calculator file my GST return?

No. It gives you a rough net GST figure so you can sense-check your own workings. You still file the actual return in myIR.

Can every business purchase be claimed?

No. You can generally claim GST on purchases used for your taxable activity, supported by proper records. Private spending, exempt-supply costs and purchases without the required information do not qualify.

What if the calculation shows a refund?

If your purchase GST is bigger than your sales GST, the return shows a refund. IRD pays it after processing the return, usually by direct credit.

When is my GST return due?

Usually the 28th of the month after your taxable period ends, with exceptions for periods ending 31 March (7 May) and 30 November (15 January). The due date guide explains the rules.