Reverse Tax Calculator

Calculate the pre-tax price from a GST-inclusive total in New Zealand.

Reverse Gst Calculator New Zealand

Use this New Zealand page when the total already includes GST and you need to find the pre-tax amount and tax component.

Pre-tax price
$104.35
Tax amount
$15.65
Total price
$120.00

At 15% tax, $120.00 gross equals $104.35 before tax and $15.65 tax. View formula

Formula

Remove tax from a total

Net price = gross total / (1 + GST rate / 100). The tax amount is the gross total minus the net price.

Example

120 at 20% becomes 100 + 20

If the total is 120 and the tax rate is 20%, the pre-tax amount is 100 and the tax amount is 20.

Accuracy

Use the exact rate

Some countries, states, provinces, and products use reduced or combined rates. Change the rate when your invoice uses a different one.

reverse gst calculator New Zealand

Built for New Zealand tax-inclusive prices

Use this New Zealand page when the total already includes GST and you need to find the pre-tax amount and tax component.

Checking a tax-inclusive invoice or receipt
Finding the net price behind a gross total
Comparing the tax amount before bookkeeping or reimbursement

Example at 15% Standard GST

$120.00 total becomes $104.35 before tax

Tax-inclusive total
$120.00
Pre-tax amount
$104.35
GST amount
$15.65

New Zealand GST rate source

The default rate is 15% Standard GST.

If a reduced, local, or product-specific rate applies, edit the rate before using the result.

New Zealand GST is commonly included in consumer prices. Use the reverse formula for GST-inclusive totals.

Rate presetRateCategory
Standard GST15%standard
Zero-rated GST0%zero

Source: New Zealand Inland Revenue

Last verified: 2026-06-24

FAQ

What GST rate does this New Zealand calculator use?

It defaults to 15% Standard GST. If your invoice uses a reduced or special rate, enter that rate manually.

Can I use this for New Zealand invoices?

Yes, for quick calculation support. Use the exact tax rate shown on the invoice and confirm compliance details with official guidance or an accountant.

Does this page include historical GST rates?

No. It focuses on the current default rate and lets you enter a custom rate when an older or special rate applies.

What is a reverse tax calculator?

A reverse tax calculator works backwards from a tax-inclusive total to estimate the pre-tax price and tax amount.

Is this tax advice?

No. This site provides calculation help only. Check official tax guidance or a qualified professional for compliance decisions.

Can I use a custom tax rate?

Yes. Enter any tax rate between 0 and 100 to match your invoice, country, state, province, or product category.

Results are for calculation support only and do not replace official tax rules, accounting advice, or professional tax guidance.