🧾 GST Calculator
Add GST to a base amount, or remove GST from a GST-inclusive price.
to see GST breakdown
Frequently Asked Questions
How do I use the GST Calculator?
Choose "Add GST" to find the GST-inclusive total from a base amount, or "Remove GST" to extract the base amount from a GST-inclusive price. Enter the amount, pick a GST rate slab (0%, 5%, 12%, 18%, 28%) or enter a custom rate, then click Calculate to see the total, base amount, GST amount, and the CGST/SGST split.
How is GST calculated on a base amount?
In "Add GST" mode, GST Amount = Base Amount × Rate / 100, and Total = Base Amount + GST Amount. For example, ₹10,000 at 18% GST gives a GST amount of ₹1,800 and a total of ₹11,800.
How do I remove GST from a price that already includes it?
Switch to "Remove GST" mode and enter the GST-inclusive amount. The calculator computes Base Amount = Total / (1 + Rate/100), and GST Amount = Total − Base Amount.
What are the standard GST slabs in India?
The common GST slabs are 0%, 5%, 12%, 18%, and 28%, applied based on the category of goods or services. Essential items are often taxed at 0% or 5%, while standard goods and services typically fall under 18%, and luxury/sin goods under 28%. You can also enter a custom rate if needed. GST rates are set by the GST Council and can change — verify the current rate for your specific goods or service on the official GST portal before filing.
What is the difference between CGST and SGST?
For intra-state transactions, the total GST is split equally between CGST (Central GST) and SGST (State GST) — each being half of the total GST amount. For inter-state transactions, the full amount is charged as IGST instead, which equals CGST + SGST combined.
Can I use this calculator for invoices and quotations?
Yes — use this tool to quickly check GST splits on any amount. For generating full GST-compliant invoices or quotations with line items, use our Invoice Generator or Quotation Generator.
A price is listed as "GST inclusive" — which mode should I use?
Use "Remove GST" mode and enter the listed (inclusive) price as the amount — the calculator extracts the base price and the GST amount baked into it. Use "Add GST" mode only when you have the base price before tax and want to find the final price a customer pays.
Why might my GST amount be off by a paisa or two compared to an invoice?
This calculator shows GST and CGST/SGST figures rounded to two decimals for display. Real invoices often round each line item's tax separately and then sum them, which can cause a difference of a paisa or two from rounding a single combined total. For exact invoice figures, use the Invoice Generator.