NZ GST Calculator

How NZ GST Works

Goods and Services Tax (GST) is New Zealand's broad-based consumption tax, charged at a flat 15% on most goods, services, and imports. Introduced in 1986 at 10% and raised to the current 15% rate in October 2010, GST is collected by GST-registered businesses at the point of sale and remitted to Inland Revenue (IRD). Because it is a single-rate tax with very few exemptions, NZ GST is widely regarded as one of the cleanest, most efficient consumption tax systems in the world.

The 15% rate applies to almost everything — retail goods, restaurant meals, professional services, digital subscriptions, and imported low-value items under the offshore GST rules. Only a short list is exempt or zero-rated, including residential rent, financial services, donated goods sold by non-profits, and exports of goods and services consumed overseas.

Who Must Register for GST

You must register for GST in New Zealand if your taxable turnover exceeds NZD $60,000 in any 12-month period, or if you reasonably expect it to cross that threshold in the next 12 months. Registration is also available voluntarily below the threshold, which can be useful if you want to claim GST back on business expenses and capital purchases.

Once registered, you must charge 15% GST on all taxable supplies, issue compliant tax invoices for sales over $50, and file GST returns either monthly, two-monthly, or six-monthly depending on your turnover. Non-resident businesses selling remote services or low-value goods into New Zealand above the $60,000 threshold are also required to register under IRD's offshore supplier rules.

Add GST vs Extract GST

There are two common GST calculations. "Add GST" takes a net (GST-exclusive) price and multiplies it by 1.15 to produce the gross price your customer pays — for example, a $100 net invoice becomes $115 including $15 GST. "Extract GST" works in reverse: you have a GST-inclusive total and need to split it into the net amount and the GST component. The correct method is to divide by 1.15 to get the net, then subtract to find the GST — or simply multiply the gross by 3/23 to isolate the GST portion directly.

A common mistake is calculating GST as 15% of the gross price — this overstates GST by roughly 13%. On a $115 gross total the GST is $15.00, not $17.25. This calculator handles both directions automatically so you never need to second-guess the maths.

GST Filing Tips

Keep every tax invoice you receive — IRD requires them to support GST credit claims on purchases over $50. Reconcile your GST return against your accounting software each period rather than waiting until the due date, and remember that GST returns are typically due on the 28th of the month after the end of your taxable period. Cash basis accounting is available for businesses with annual turnover under $2 million and can smooth cash flow by aligning GST payments with when money actually changes hands. For complex situations — mixed-use assets, property transactions, second-hand goods — consult a chartered accountant or IRD directly at ird.govt.nz.

This calculator uses the current 15% NZ GST rate and runs entirely in your browser — no amounts or invoices ever leave your device.