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GST Calculator

Calculate GST on any amount, both directions. Exclusive mode adds GST to a pre-tax amount; Inclusive mode extracts the GST component from a total that already has GST. Updated for 2026 GST 2.0 rates (0%, 5%, 18%, 40%). For historical invoices that used the older 12% slab, use the Custom rate field.

%
Total payable
₹0.00
Enter an amount to begin
CGST (9%) ₹0.00
SGST (9%) ₹0.00
Total amount ₹0.00

How GST is calculated

The math is straightforward but most online calculators get the reverse calculation wrong. Here are the formulas this calculator uses, with worked examples.

Adding GST (exclusive → inclusive): if you have a base amount and need to add GST on top.

Forward calculation
GST amount = base × (rate / 100)
Total = base + GST amount = base × (1 + rate / 100)

Example: a base amount of ₹1,000 at 18% GST. GST = 1,000 × 0.18 = ₹180. Total = ₹1,180.

Extracting GST (inclusive → exclusive): if you have a GST-inclusive total and need to find the base amount and the GST component. This is where most calculators go wrong: they subtract the rate as a percentage of the inclusive total, which gives the wrong base amount.

Reverse calculation (correct method)
Base = total ÷ (1 + rate / 100)
GST amount = total − base

Example: a GST-inclusive total of ₹1,180 at 18%. Base = 1,180 ÷ 1.18 = ₹1,000. GST = 1,180 − 1,000 = ₹180. (The wrong method, subtracting 18% from 1,180, would give ₹967.60, which is incorrect.)

Intra-state vs inter-state split. For supplies within the same state, GST is split equally into CGST (Central GST) and SGST (State GST), each at half the headline rate. For supplies across state lines or exports, the full rate applies as IGST (Integrated GST). The total tax is identical either way; only the split differs.

The 2026 GST rates

India's GST structure was overhauled on 22 September 2025 under GST 2.0, simplifying the previous multi-slab system into a cleaner structure. Older slabs were largely scrapped, with items shifted to 5%, 18%, or a new 40% rate for luxury and sin goods.

0%
Nil-rated and exempt items. Essential foodgrains, fresh produce, education services, individual health and life insurance.
5%
Merit rate. Daily essentials, packaged food, soap, toothpaste, shampoo, agricultural equipment, transport services.
18%
Standard rate. Most goods and services, including consumer electronics, mobile phones, restaurants, professional services, small cars, and most B2B supplies.
40%
Sin and luxury rate. Premium cars, betting and online gaming, aerated drinks, motorbikes above 350cc. Tobacco and pan masala move at a later date pending compensation cess settlement.
3%
Special rate. Gold, silver, and other precious metals.

For historical invoices dated before 22 September 2025, you can use the Custom field above to enter legacy rates such as 12%. Always issue current invoices at the post-GST-2.0 rates; using old rates on new invoices creates compliance issues.

FAQ

Intra-state (supplier and recipient in the same state): GST splits equally into CGST (goes to central government) and SGST (goes to state government). For example, 18% GST splits into 9% CGST + 9% SGST. Inter-state (supplier and recipient in different states, or exports): full rate applies as IGST, which is later distributed between central and state governments. The total tax paid is identical either way; only the accounting split differs.
No, not for new invoices. The 56th GST Council meeting (3 September 2025) approved GST 2.0, effective 22 September 2025. The 12% slab was scrapped, with items moving to either 5% or 18%. For historical invoices dated before 22 September 2025, use the Custom field in the calculator above to enter 12% (or any other legacy rate).
Use the Inclusive mode. The formula is: base = total ÷ (1 + rate/100). So for a GST-inclusive amount of ₹1,180 at 18%, base = 1,180 ÷ 1.18 = ₹1,000, and the GST component is ₹180. Do not subtract 18% from 1,180 directly, that gives ₹967.60, which is wrong.
Determined by the place of supply: if it's in the same state as your registered location, charge CGST + SGST. If it's in a different state (or it's an export), charge IGST. For services, place of supply rules are more nuanced (default location of recipient for B2B, location of supplier for B2C), but the same intra-state vs inter-state principle applies.
Threshold: ₹40 lakh annual turnover for goods in most states (₹20 lakh in special category states), and ₹20 lakh for services in most states (₹10 lakh in special category states). Mandatory registration regardless of turnover for: inter-state suppliers, e-commerce operators, casual taxable persons, non-resident taxable persons, and a few other categories. For a detailed walk-through see our GST Registration page.
No. This is a single-transaction calculator for quick checks. For actual GST return filing (GSTR-1, GSTR-3B, GSTR-9), input tax credit reconciliation, e-invoicing, and multi-transaction handling, you need GST filing software (Zoho Books, Tally, ClearTax, etc.) or a CA. If you need the filing done by humans, see our GST Returns page.
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GST Registration
Centre + State GSTIN, 7-12 days, all documents handled. For new businesses crossing the threshold.
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