How to Correctly Calculate Goods & Services Tax Costs for New Zealand
These New Zealand GST calculators work out:
Enter any known amount into the appropriate box to calculate the other 2 figures.
Basic GST Calculations.
Goods and Services Tax in NZ is 15%
To add 15% GST onto $100
Inland Revenue (IRD) recommends the following formula to find the GST amount from a GST inclusive price.
Working backwards to find the GST and GST exclusive amounts from the total GST inclusive price.
To work out the GST exclusive amount simply subtract the GST from the GST inclusive amount to get the original GST exclusive cost.
We're now back to the start with a GST exclusive price.
When using the correct formula, you can see the $15 GST cost remains the same when adding GST on and finding the GST amount from the inclusive price.
Just subtracting 15% from the GST inclusive price won't work.
To subtract 15% from our $115 GST inclusive figure from above…