GST Calculator

What is a GST calculator?

A GST calculator is an online tool that works out the Goods and Services Tax on an amount instantly, without manual formulas. Enter a price, pick a GST rate, and it shows you the tax amount and the final total — useful for shopkeepers, freelancers, accountants, and anyone billing customers in India.

How do I use this GST calculator online?

Type an amount on the keypad, tap a GST rate (0%, 5%, 18%, or 40% under the current GST 2.0 structure), and choose Add GST or Remove GST. The result updates live, showing CGST, SGST, IGST, and the total — no separate "calculate" button needed.

What's the difference between a GST calculator inclusive and exclusive of tax?

GST exclusive means the amount you enter doesn't include tax yet — the calculator adds GST on top to find the final price. GST inclusive means the amount already has tax baked in — the calculator works backward to extract the tax portion and find the original taxable value. This calculator handles both: "Add GST" mode is exclusive, "Remove GST" mode is inclusive.

What is a reverse GST calculator?

A reverse GST calculator (also called a GST extraction calculator) takes a final price that already includes tax and works out the original amount before GST, plus the tax component itself. For example, if a product costs ₹1,180 with 18% GST included, a reverse GST calculator shows the taxable value was ₹1,000 and the GST was ₹180. Use "Remove GST" mode on this calculator for that.

What's the difference between CGST, SGST, and IGST?

For sales within the same state (intra-state), GST splits equally into CGST (Central GST, collected by the central government) and SGST (State GST, collected by the state government) — each is half the total GST rate. For sales between different states (inter-state), the full GST is charged as IGST (Integrated GST), collected by the central government and apportioned to the destination state. This calculator switches between the two automatically using the Intra-state/Inter-state toggle.

How do I calculate GST percentage manually?

For GST exclusive amounts: GST Amount = (Original Amount × GST Rate) ÷ 100, then add that to the original amount for the total. For GST inclusive amounts: Taxable Value = Total Amount ÷ (1 + GST Rate ÷ 100), and GST Amount = Total Amount − Taxable Value. For example, on ₹1,000 at 18% GST exclusive, the GST amount is ₹180 and the total is ₹1,180.

What are the current GST rates in India (GST 2.0)?

Since the GST 2.0 reform took effect on 22 September 2025, India's GST structure has four main slabs: 0% for essentials (fresh food, healthcare, education), 5% for daily-use and mass-consumption goods, 18% as the standard rate covering most goods and services, and 40% for select luxury and sin goods like tobacco, pan masala, and premium vehicles. The earlier 12% and 28% slabs were merged into 5% and 18% respectively for most items.

Which goods and services fall under each GST slab?

The four GST 2.0 slabs cover different categories of goods and services based on whether they're essential, standard, or luxury items:

• 0% (Exempt): Unpacked food items, fresh fruits and vegetables, milk, bread, salt, and certain healthcare and education services.
• 5%: Daily household essentials such as soaps, hair oil, and toothpaste, along with dairy products, agricultural goods, and diagnostic medical equipment.
• 18% (Standard rate): Most consumer electronics (TVs, ACs, dishwashers), two-wheelers, small cars, and general services.
• 40% (Sin & luxury): Demerit and luxury goods such as tobacco products, pan masala, and high-end luxury vehicles.

Use the rate buttons on this calculator to apply the correct slab once you know which category your item falls under.

Why doesn't this calculator show 12% or 28% GST by default?

Those rates were phased out for most goods and services under the new GST rate calculator structure effective September 2025. They're still useful for older invoices, historical comparisons, or specific composition-scheme cases, so this calculator keeps them available — tap "Need old rates (12% / 28%)?" below the rate buttons to switch to the legacy GST calculator with old slabs.

Can I calculate 18 percent GST or other specific rates directly?

Yes — tap the matching rate button (5%, 18%, or 40%) and the breakdown updates instantly. This works as a dedicated 18% GST calculator, 5% GST calculator, or 40% GST calculator depending on which rate you select, with no need to type the percentage manually.

Is this GST calculator free to use?

Yes, it's completely free with no sign-up required. All calculations happen instantly in your browser.

Does this work as a GST calculator app or GST calculator extension?

This calculator is built to feel like a real calculator app — full keyboard support, calculation history, and a keypad-driven interface rather than a plain input form. A dedicated browser extension version is in the works for quick access without opening a new tab.

Can I see my past GST calculations?

Yes — tap the history icon at the top of the calculator to open a saved list of past calculations. Each entry shows the amount, rate, and breakdown, and can be copied, shared, or tapped to reload back into the calculator.

What is the GST formula for calculating tax on an invoice?

The standard GST calculation formula for invoices is: GST Amount = (Taxable Value × GST Rate) ÷ 100. If the transaction is within the same state, split that GST amount equally between CGST and SGST. If it's an inter-state transaction, the full amount is charged as IGST. This calculator applies the correct formula automatically based on the mode and rate you select.