How to Calculate GST Content When GST is 15%

Posted 27/05/2010 Updated 11/06/2012

Here's the formula used to work out the GST content of a GST inclusive price when the GST content is 15%

Multiply the full GST inclusive price by 3 then divide that result by 23. The end result will be the GST amount.

The above formula is the Inland Revenue recommended method of calculating the GST content of a GST inclusive amount. Goods & Services Tax in New Zealand changed from 12.5% to 15% on 1 October 2010.

Update 1: Here's a few super easy GST calculators for working this out.

Update 2: Here's a full explanation and examples on how to work out GST correctly at 15%.

Related Items: GST

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