GST Calculator

Manual GST calculation is a single multiplication, but errors compound quickly when you handle multiple invoices at different rates, need to split tax between CGST and SGST line items, or must distinguish between base prices and inclusive prices in client negotiations.

This calculator is particularly useful in these scenarios:

• Raising GST-compliant invoices: The GST Act requires registered businesses to show CGST and SGST as separate line items on every intra-state tax invoice. This calculator gives you both figures instantly, reducing the chance of invoice errors that delay payment or ITC claims.
• Client quotes and project proposals: A freelancer quoting ₹1,00,000 for a project at 18% needs to be explicit, is that the base price (total payable ₹1,18,000) or an inclusive figure (base ~₹84,746)? Getting this right before the engagement starts prevents payment disputes at billing time.
• Capital expenditure planning: A business purchasing equipment worth ₹5,00,000 at 12% GST faces a total outgo of ₹5,60,000, the ₹60,000 GST component affects immediate cash flow even if it will eventually be recovered as ITC.
• Verifying MRP-tagged purchases: Packaged goods in India carry GST-inclusive MRPs. Use the reverse GST formula to confirm whether a product's stated price is consistent with the declared tax rate.

For freelancers and small business owners, understanding your monthly GST outflows is also foundational to investment planning, once you know your net income after tax, you can model what a fixed monthly investment might grow to. Our SIP Calculator can help quantify how even modest monthly surpluses compound significantly over a 10–15 year horizon.

Freelancers and independent consultants raising invoices for professional services. Most freelance work, software development, UI/UX design, content writing, legal advisory, and management consulting, falls under the 18% GST slab. GST registration becomes mandatory once annual revenue crosses ₹20 lakhs, after which every invoice must display CGST and SGST as separate statutory line items.

Small business owners and traders selling goods across multiple slabs. A retailer who sells both packaged food (5%) and electronics (18%) in the same transaction needs accurate per-item GST to file correct GSTR-1 and GSTR-3B returns each month.

Finance professionals and accountants, CAs, bookkeepers, and accounts executives, who need a fast sanity check on tax amounts before approving purchase orders, processing vendor invoices, or reconciling GSTR-2A credit data.

Students preparing for Commerce, CA Foundation, or MBA entrance exams, where GST computation is a standard topic. This calculator is a reliable way to verify manual workings and build intuition around different rate slabs.

Consumers and end customers who want to confirm that a restaurant bill, e-commerce order invoice, or telecom bill correctly applies the stated GST rate. Billing errors in B2C contexts, especially in restaurants and professional services, are more common than most customers realise.

Business owners who systematically track their post-tax income often allocate a fixed monthly amount towards long-term savings. Our SIP Calculator shows how those regular investments compound over time, making it a natural companion to tax planning tools.

The calculator returns four outputs, each serving a distinct purpose in real-world compliance and financial decisions.

GST Amount is the primary result, the tax you add on top of your base price and eventually remit to the government (net of input tax credits you are entitled to claim). This figure flows directly into your GST return as output tax liability. If the amount appears unexpectedly high, verify that you selected the correct slab, misclassifying a 12% item as 18% is a common source of inflated invoices and disputes.

Total (incl. GST) is the GST-inclusive price, the amount the buyer actually pays. For B2C invoices such as restaurant bills and retail receipts, this is the headline figure. For B2B invoices, both the base price and the tax amount matter equally: the buyer uses the base for expense accounting and the GST amount for ITC claims.

CGST is the Central Government's share, always exactly half the total GST for intra-state transactions. This must appear as a separate line item (e.g. "CGST @ 9%") on every tax invoice raised under the GST Act for an intra-state supply.

SGST / UTGST is the State or Union Territory Government's share, also exactly half the total GST. For supplies within states like Karnataka, Maharashtra, or Tamil Nadu, this will be SGST; for Union Territories, it will be UTGST. The amount is always numerically identical to CGST.

A key diagnostic: if you receive an invoice where CGST and SGST are unequal, or their sum does not match the stated total GST, the invoice contains an error and may need to be revised before you can legally claim ITC on it.

For business owners who factor monthly GST outflows into their financial planning, the net income after tax informs how much can be invested systematically, our SIP Calculator makes it straightforward to model how those monthly surpluses can grow into a meaningful corpus over time.

1. Enter the Amount (Exclusive of GST), this is the base price of your goods or services before any tax is added. For an invoice you are raising, this is your fee or product price. If you already have a GST-inclusive figure (such as an MRP), divide it by (1 + GST Rate ÷ 100) first to arrive at the base, for example, ₹1,18,000 at 18% yields a base of ₹1,00,000.

2. Select the GST Rate, choose the slab applicable to your goods or service: 5% for essential goods, 12% for standard goods, 18% for most services and manufactured goods, or 28% for luxury and demerit goods. If you are unsure of the correct slab, look up the HSN code (Harmonised System Nomenclature, for goods) or SAC code (Services Accounting Code, for services) in the GST Council's official rate schedule.

3. Read the GST Amount, the highlighted output shows the total tax to be charged. This is the amount you collect from your buyer and, net of eligible input tax credits, remit to the government via your monthly or quarterly GST return.

4. Note the CGST and SGST split, for intra-state invoices, both figures must appear as separate line items on your tax invoice. Each is exactly half the total GST. If your transaction is inter-state, neither CGST nor SGST applies, only IGST at the full combined rate.

5. Use Total (incl. GST) as your invoice total, this is the bottom-line amount your client pays. Print this as the invoice total and include base price, CGST, and SGST as supporting line items above it to produce a GST-compliant invoice format.