Do you need to add GST? Or subtract GST? Feel free to use our NZ GST calculator when ever you need to be working out GST.
This dead simple tool is easy to use so make sure you save this page to your Favourites/Bookmarks for quick future reference.
To manually calculate GST at 15% you need to simply use one of the 2 below formulas:
Amount + (Amount x GST Rate)
= $100 + ($100 x 0.15)
= $100 + ($15)
(Amount x 3) / 23
= ($100 x 3) / 23
= ($300) /23
Use our NZ GST Calculator above to double check your calculations are correct.