Free tool
GST calculator
Add or remove GST for any slab and get an instant CGST/SGST or IGST breakdown. Free, no signup — the same math powers the PocketGST app offline.
Free tool · Live
GST calculator
Updates as you type · CGST / SGST split
Result
Save GST calculations with history — offline
PocketGST keeps add/remove GST history, lets you reuse amounts, and converts any calculation into a GST invoice. Works without internet at your desk or on the road.
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How to calculate GST
- 1
Pick a mode
Choose Add GST to build a price from a base amount, or Remove GST to extract the base from an inclusive total.
- 2
Enter the amount
Type the taxable value (Add) or the GST-inclusive total (Remove). The result updates live as you type.
- 3
Choose the GST slab
Tap 0%, 5%, 18%, or 40% (or 3% for gold). The calculator splits the tax into CGST and SGST automatically.
- 4
Copy or share
Copy the breakdown for a quote, or open PocketGST to turn it straight into a GST invoice.
GST slabs in India
| GST rate | Common examples |
|---|---|
| 0% / Exempt | Fresh produce, unbranded food grains, books, insurance |
| 3% | Gold, silver, and other precious metals |
| 5% (merit) | Packaged staples, soaps, medicines, apparel up to ₹2,500 |
| 18% (standard) | Most goods & services, electronics, cement, small cars |
| 40% (de-merit) | Aerated drinks, luxury cars, tobacco, betting |
Rates are indicative and can change with GST Council notifications. Confirm the exact rate for your HSN/SAC code before issuing tax invoices.
FAQ
GST calculator FAQs
How does the GST calculator work?+
Pick Add GST to find the total from a base amount, or Remove GST to find the base from a GST-inclusive total. Choose a slab (0%, 5%, 18%, 40%, or 3% for gold) and the calculator instantly shows the taxable value, CGST/SGST split, and total.
How is CGST and SGST calculated?+
For intra-state supplies, GST is split equally into CGST and SGST. At 18%, that is 9% CGST + 9% SGST. For inter-state supplies, the same total is charged as a single IGST line instead.
What is the formula to add GST?+
Total = Base × (1 + GST%/100). Example: ₹10,000 + 18% GST → ₹10,000 × 1.18 = ₹11,800, made up of ₹900 CGST and ₹900 SGST.
What is the formula to remove GST?+
Base = Total ÷ (1 + GST%/100). Example: ₹11,800 inclusive of 18% GST → ₹11,800 ÷ 1.18 = ₹10,000 taxable value, ₹1,800 GST.
Is this GST calculator free and offline?+
The web calculator is free with no signup. Install the PocketGST Android app to calculate offline, save history, and turn results into GST invoices.