GST Calculator
Calculate GST amount, GST-inclusive and GST-exclusive prices. Free, fast and private.
Your result will appear here.
Formula: Add GST — GST = amount × rate ÷ 100, total = amount + GST. Remove GST — base = total ÷ (1 + rate ÷ 100), GST = total − base. Rates shown are common slabs; use the rate that applies to your item.
How to use GST Calculator
- Enter the amount.
- Choose the GST rate that applies (5%, 12%, 18% or 28%).
- Choose Add GST or Remove GST, then click Calculate GST.
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
How do I add GST to a price?
GST = price × rate ÷ 100, then add it to the price. At 18%, a 10,000 item costs 11,800 with GST.
How do I remove GST from a price?
Base price = price including GST ÷ (1 + rate ÷ 100). The GST is the difference between the total and the base price.
What GST rates are used here?
The common slabs 5%, 12%, 18% and 28% (plus 0%). The correct rate depends on the item — check the applicable slab.
Is this GST calculator free?
Yes, it is 100% free with no sign-up. Your data stays in your browser.