GST calculator.
CGST · SGST · IGST.
Add GST to a base amount, or strip it out of a gross invoice. Picks CGST + SGST for intra-state supply and IGST for inter-state automatically.
Same state → CGST + SGST applied at half-rate each.
This calculator follows CGST Act §9 + IGST Act §5. For composite or mixed supplies, consult your CA — LexVio's Tax AI handles those cases automatically.
Common GST rates in India.
Understanding GST in India
Goods and Services Tax (GST) is India's unified indirect tax, in force since 1 July 2017. It replaced a stack of state and central taxes — VAT, service tax, excise, octroi — with a single, destination-based tax administered jointly by the Centre and the states.
For any taxable supply you make, the GST due depends on three things: the rate slab (set by HSN/SAC), whether the transaction is intra-state or inter-state, and whether the price you quoted is inclusive or exclusive of tax. This calculator handles all three.
CGST + SGST or IGST — which applies?
When the place of supply and the supplier are in the same state, GST splits 50/50 into CGST (Central) and SGST (State). When they're in different states, the entire tax goes to IGST (Integrated GST), which is later apportioned between the Centre and the destination state.
For services, place of supply is generally the recipient's registered address. For goods, it's where the goods are delivered. Get this wrong and you raise the wrong invoice — which means a notice from the GSTN and a manual amendment in GSTR-1.
Inclusive vs exclusive pricing
An exclusive price means GST is added on top — you quote ₹10,000 and charge ₹11,800 at 18%. An inclusive price means the headline figure already contains GST — ₹11,800 inclusive of 18% works back to a base of ₹10,000 + ₹1,800 tax. B2B invoices typically quote exclusive; B2C menus, MRPs and SaaS subscriptions are usually inclusive.
What this calculator does not handle
For clarity, these scenarios need more than a calculator — they need filings or AI review:
- Reverse charge — where the recipient pays GST instead of the supplier (legal services, freight, imports).
- Composition scheme — flat-rate GST for turnover under ₹1.5 crore; rates differ.
- E-invoicing thresholds — mandatory once turnover crosses ₹5 crore.
- Input tax credit (ITC) — netting input GST against output GST in your GSTR-3B.
Frequently asked
What is the difference between CGST, SGST and IGST?
CGST and SGST apply when the supplier and the place of supply are in the same state — each takes half the GST. IGST applies when they're in different states; the whole tax goes to the Centre, which apportions it to the destination state. UTGST replaces SGST in Union Territories without a legislature.
When should I use inclusive vs exclusive pricing?
Use exclusive when you raise B2B invoices — the customer expects tax shown separately so they can claim Input Tax Credit. Use inclusive for B2C menus, MRPs, retail price tags, and SaaS subscriptions where the headline number is what the customer pays.
Does this calculator handle reverse charge?
No. Reverse Charge Mechanism (RCM) — where the recipient pays GST instead of the supplier — applies to legal services, freight, imports of services, and notified goods/services. RCM treatment is filing-side, not invoice-side, so a calculator isn't enough; you need it reflected in your GSTR-3B.
Which GST rate applies to my product or service?
Rates are tied to HSN codes (goods) and SAC codes (services). 0% covers most fresh food, books, and healthcare. 5% covers essential goods. 12% and 18% are the common slabs. 28% is luxury and sin goods (cars, tobacco, aerated drinks). Use our HSN/SAC finder to look up your code.
Is e-invoicing required for me?
E-invoicing under the GST e-invoice portal (IRN/QR code) is mandatory for taxpayers with aggregate annual turnover above ₹5 crore in any prior year from 2017-18 onwards. Below that, you can raise tax invoices in your own format. The threshold has dropped every year, so re-check annually.
Can I claim Input Tax Credit on the GST I pay?
Generally yes, if the input is used in the course of business and you have a valid tax invoice. ITC is blocked for items like motor vehicles (with exceptions), club memberships, personal consumption, and works contracts for immovable property (except plant and machinery). ITC is netted against output GST in GSTR-3B.
What is the composition scheme?
An optional simpler scheme for taxpayers with turnover under ₹1.5 crore (₹75 lakh for special-category states). Pay a flat rate (1% traders, 5% restaurants, 6% services up to ₹50 lakh) on turnover, no ITC, and file quarterly. Not available for inter-state suppliers or e-commerce sellers.