GST calculator
Add GST to an amount, or take it out of a price that already includes it.
Rupees One Thousand One Hundred Eighty Only
As per current rules, last checked on 12 November 2026. The rate depends on the HSN or SAC code of what you sell. Verify on the GST portal.
How the numbers are worked out
Adding GST. GST = amount × rate ÷ 100. Total = amount + GST.
Taking GST out. Value before GST = price × 100 ÷ (100 + rate). GST = price − value before GST.
For a sale within one state the GST is split into two equal halves, CGST and SGST. Each half is rounded to the paisa, as on an invoice.
About this calculator
How is GST taken out of a price that already includes it?
Divide the price by (100 + GST rate) and multiply by 100 to get the value before tax. The difference is the GST. For example, 1,180 at 18% gives 1,000 before tax and 180 of GST.
Which GST rates apply now?
Since 22 September 2025 most goods and services are taxed at 5% or 18%. A 40% rate applies to a short list of goods and services, and special rates such as 3% and 0.25% continue for items like gold and rough diamonds. The rate depends on the HSN or SAC code, so check yours before you invoice.
When is it CGST and SGST, and when is it IGST?
For a sale within one state, the tax is split equally into CGST and SGST (UTGST in some union territories). For a sale to another state, the whole tax is IGST.
Stop working out GST by hand
SG Works ERP works out the tax on every invoice from the product’s GST rate and the buyer’s state. We reply within 24 hours on business days.