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Total amount
For inter-state supplies, use full GST as IGST instead of splitting it into CGST and SGST.
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Goods and Services Tax (GST) is an indirect tax on supply of goods and services in India. Depending on the transaction, GST may be charged as CGST and SGST for intra-state supplies or as IGST for inter-state supplies.
How this GST calculator works
Enter an amount and GST rate. Leave the checkbox off to add GST to a base amount, or tick it if the amount already includes GST and you want to reverse-calculate the base and tax. Figures are indicative only, not advice.
What is GST?
Goods and Services Tax (GST) is India's unified indirect tax on the supply of goods and services, introduced on 1 July 2017 to replace a web of older taxes like VAT, service tax and excise. It is a destination-based, multi-stage tax collected at every point in the supply chain, but businesses claim credit for the tax they paid on inputs, so the final tax burden falls on the end consumer. GST is administered jointly by the central and state governments through the GST Council.
GST rate slabs in India
Most goods and services fall into one of a few standard rate slabs. The exact rate depends on the item and is decided by the GST Council:
- 0% (exempt / nil-rated): essential items such as fresh produce, unbranded food grains and many healthcare and education services.
- 5%: common household necessities, packaged food staples and economy transport.
- 12%: processed foods, business-class air travel and several standard goods.
- 18%: the most common slab — most services, electronics and industrial goods.
- 28%: luxury and "sin" goods such as high-end cars, tobacco and aerated drinks, sometimes with an additional cess.
Always confirm the current rate for your specific item, as the Council revises slabs from time to time.
CGST, SGST and IGST — how the tax splits
The same total GST rate is collected differently depending on where the buyer and seller are located:
- Intra-state supply (buyer and seller in the same state): the tax is split equally into CGST (to the centre) and SGST (to the state). For 18% GST, that's 9% CGST + 9% SGST.
- Inter-state supply (different states) and imports: a single IGST equal to the full rate is charged, which the centre later shares with the destination state.
The calculator above shows the CGST/SGST split for intra-state supplies; for inter-state supplies the same total is simply charged as IGST.
Input Tax Credit and GST registration
A key feature of GST is Input Tax Credit (ITC): a registered business can deduct the GST it paid on purchases from the GST it collects on sales, paying only the difference. This avoids the old "tax-on-tax" cascade. Businesses must register for GST once their turnover crosses the threshold (broadly ₹40 lakh for goods and ₹20 lakh for services, lower in some special-category states), and file periodic returns. This calculator is meant for quick invoice-level estimates, not for filing returns.
Frequently asked questions
How do I add GST to an amount?
When the amount is exclusive of GST, GST equals amount × rate ÷ 100 and the total equals amount plus GST. The calculator also splits GST equally into CGST and SGST for intra-state supplies.
How do I remove GST from an inclusive amount?
When the amount already includes GST, the base amount equals total × 100 ÷ (100 + rate). GST is the difference between the total and the base amount.
What is the difference between CGST, SGST and IGST?
For intra-state supplies GST is usually split equally into CGST and SGST. For inter-state supplies, the same total GST is charged as IGST instead of a CGST/SGST split.
What are the GST rate slabs in India?
The main slabs are 0%, 5%, 12%, 18% and 28%, plus an additional cess on some luxury and sin goods. 18% is the most common rate for services and many goods. The GST Council revises these from time to time, so confirm the current rate for your item.
Who needs to register for GST?
Broadly, businesses must register once turnover crosses ₹40 lakh for goods or ₹20 lakh for services (lower in some special-category states). Registered businesses can claim Input Tax Credit on their purchases and must file periodic GST returns.