How To Calculate NZ GST?

If you are wondering how to calculate NZ GST you have come to the right place. In This guide we are going to explain how you can calculate the GST exclusive price, inclusive price, and GST component.

Calculating From GST Exclusive Price

If you have the GST exclusive price and want to find out how much the gst inclusive price and GST component is you can do the following:

The Right Way

GST Inclusive:

GST Inclusive Price = GST Exclusive Price x 115%

GST Inclusive Price = $100 x 1.15

GST Inclusive Price = $115

GST Component:

GST Component = GST Inclusive Price x 15%

GST Component = $100 - 0.15

GST Component = $15

GST Inclusive Price if you already have both the Exclusive Price and Component:

GST Inclusive Price = GST Exclusive Price + GST Component

GST Inclusive Price = $100 x $15

GST Inclusive Price = $115

GST Component if you already have both the Inclusive and Exclusive Price:

GST Component = GST Inclusive Price - GST Exclusive Price

GST Component = $115 - $100

GST Component = $15

Calculating From GST Inclusive Price

If you are working from the GST inclusive price and want to find the exclusive price and GST component it is easy to get tripped up. It's not as simple as just doing the opposite of what we just did above:

The Right Way

GST Component:

GST Component = GST Inclusive Price x 3 ÷ 23

GST Component = $115 x 3 ÷ 23

GST Component = $15

GST Exclusive Price:

GST Exclusive Price = GST Inclusive Price - GST Component

GST Exclusive Price = $115 - $15

GST Exclusive Price = $100

The Wrong Way

GST Component:

GST Component = GST Inclusive Price - 15%

GST Component = 115 x 0.15

GST Component = $17.25

GST Exclusive Price:

GST Exclusive Price = GST Inclusive Price - GST Component

GST Exclusive Price = $115 - $17.25

GST Exclusive Price = $97.75

As you can see this is not the correct GST exclusive value if we compare it to the calculations in the "Calculating From GST Exclusive Price" section (we started with $100). This is because if we simply minus 15%, we wind up with a GST component of $17.25, not the correct $15 amount.

Calculating From GST Component/Amount

If you only have the GST component/amount, you can work out the GST inclusive and exclusive price by essentially reversing the formula we gave you just above:

The Right Way

GST Component:

GST Inclusive Price = GST Component x 23 ÷ 3

GST Inclusive Price = $15 x 23 ÷ 3

GST Inclusive Price = $115

GST Exclusive Price:

GST Exclusive Price = GST Inclusive Price - GST Component

GST Exclusive Price = $115 - $15

GST Exclusive Price = $100

Use Our Calculator

If you don't won't to do this all yourself, check out our handy calculator here. Alternatively, if you want to learn how to apply this formula in excel you can do so by checking out this article.