GST Calculator
Add or remove Goods and Services Tax (GST / VAT) arithmetic calculations from net or gross prices.
Gross amount (incl. GST)
$118.00
$18.00gst tax amount•
$100.00net price•
$118.00gross price
Calculate Goods and Services Tax (GST) or Value Added Tax (VAT) additions and extractions.
[!NOTE] This calculator provides pure mathematical percentage calculations for tax-inclusive and tax-exclusive amounts. It does not constitute official tax or legal advice.
Formulas & Method
Adding GST (Net → Gross)
- GST Amount:
Net Amount × (GST % ÷ 100) - Gross Amount:
Net Amount + GST Amount
Removing GST (Gross → Net)
- Net Amount:
Gross Amount ÷ (1 + GST % ÷ 100) - GST Amount:
Gross Amount - Net Amount
Worked Example
For an amount of $100 at an 18% GST rate:
- Adding GST:
$100 Net + $18 GST = $118 Gross - Removing GST (from $118 Gross):
$118 ÷ 1.18 = $100 Net($18 Tax)
Frequently Asked Questions
How do I add GST to an amount?+
Multiply the net amount by the GST rate percentage, then add the resulting tax to the original net amount.
How do I remove GST from an inclusive total?+
Divide the gross inclusive total by (1 + GST rate / 100) to find the original net price.
Is this tax tool providing legal or accounting advice?+
No. This tool is a general arithmetic calculator for percentage additions and removals. It does not provide legal or tax guidance.
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