🧾 GST & Sales Tax Calculator

How to Add or Remove GST

1. Enter the amount you are working with.
2. Type the tax rate, or tap one of the common rate buttons.
3. Choose Before tax to add tax to a net figure.
4. Choose Tax included to extract the tax from a price that already contains it.
5. Read the net, tax and gross amounts — plus the CGST/SGST split for Indian invoices.

How do I remove tax from an inclusive price?

You divide, not subtract. To remove 18% GST from 1,180 you divide by 1.18, giving 1,000 net and 180 tax. Subtracting 18% of 1,180 would wrongly give 967.60, because the 18% was calculated on the net amount rather than the gross. Selecting Tax included handles this automatically.

What is the difference between GST, VAT and sales tax?

GST and VAT work the same way: tax is charged at each stage of the supply chain, and businesses reclaim what they paid on inputs, so only the final consumer bears the full cost. US sales tax is different — it is charged only once, at the point of final sale, and rates are set by state and often by city. The arithmetic in this calculator applies to all three.

Why is the tax split into CGST and SGST?

For sales within a single Indian state, GST is divided equally between the central government (CGST) and the state government (SGST), so 18% GST appears on the invoice as 9% CGST plus 9% SGST. For sales between states a single IGST at the full rate applies instead. The split shown here is half the total tax, which is what you enter on an intra-state invoice.

Which rate should I use?

It depends on the product and the country. Indian GST has slabs of 0%, 5%, 12%, 18% and 28% depending on the category. UK VAT is generally 20% with a reduced 5% rate and a zero rate for essentials. Australian GST is a flat 10%. Because rates change and categories are frequently reclassified, confirm the current rate for your specific goods with your tax authority or accountant.