GST Calculator

Add or remove GST for all 5 slabs — reverse GST too

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GST Calculator is a free, browser-based tool that lets you add or remove gst for all 5 slabs — reverse gst too — with zero signup, zero installation. Your data never leaves your browser. Part of 116+ free developer and business tools at wowhow.cloud, built and maintained by a team with 14+ years of hands-on development experience.

TOOLGST Calculator

Amount (Rs)

₹10,000.00

Mode

Transaction Type

Quick:

Add GST: Enter the base/exclusive price. GST is calculated on top of this amount.

Results — All GST Slabs

GST Rate	Base Amount	CGST	SGST	Total (GST incl.)
0%	₹10,000.00	—	—	₹10,000.00
5%	₹10,000.00	₹250.00	₹250.00	₹10,500.00
12%	₹10,000.00	₹600.00	₹600.00	₹11,200.00
18%most common	₹10,000.00	₹900.00	₹900.00	₹11,800.00
28%	₹10,000.00	₹1,400.00	₹1,400.00	₹12,800.00

Your Amount (Base)

₹10,000.00

GST @ 18% (CGST + SGST)

₹1,800.00

Total Payable

₹11,800.00

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About GST Calculator

Every Indian business transaction involves a GST decision: which slab, add or reverse, CGST+SGST or IGST? Getting it wrong — even by applying CGST+SGST on an inter-state sale — can cause invoice mismatches in GSTR-2B and ITC disputes. This calculator shows all five slabs simultaneously and lets you toggle between add-tax and remove-tax (reverse) modes, so you see the full picture before raising an invoice or reconciling a purchase.

How It Works

In Add GST mode, the tool computes: GST Amount = Base Price × Rate / 100, and Total = Base Price + GST Amount. This is the amount you charge the buyer and collect to remit to the government. For intra-state supplies, GST splits equally: CGST = SGST = Rate/2. For inter-state, IGST = full rate.

In Remove GST mode (reverse calculation), the tool extracts the base price from a GST-inclusive total: Base = Inclusive Total / (1 + Rate/100). This is useful when you receive a GST-inclusive invoice and need to separate the tax component for your books or ITC claim.

All five GST slabs (0%, 5%, 12%, 18%, 28%) are shown simultaneously, making it easy to verify the right slab for your product or service without switching back and forth.

Who Is This For

A freelance consultant raising a GST invoice for a client in a different state, confirming that IGST at 18% applies rather than CGST+SGST.

A retailer receiving goods with an MRP-inclusive price, needing to extract the base price and GST component for accounting.

An accounts executive reconciling purchase invoices and verifying the GST amounts match the supplier-declared values.

A small business owner trying to decide whether their product falls under 12% or 18% by comparing the tax impact on final price at both slabs.

Scope note: Uses the five standard GST rate slabs as per the GST rate schedule. Does not cover Compensation Cess (levied on top of 28% for certain goods), composition scheme rates, exempt supply rules, or RCM (Reverse Charge Mechanism) transactions. For precise HSN/SAC classification and applicable rate, use the HSN & SAC Code Finder tool or consult a GST practitioner.

How to Use

Enter any amount in the input field

Toggle between "Add GST" and "Remove GST" modes

View results for all 5 GST slabs simultaneously

Switch between Intra-state (CGST+SGST) and Inter-state (IGST) view

Frequently Asked Questions

To add GST: GST Amount = Base Price x GST Rate / 100. Total = Base Price + GST Amount. To remove GST from inclusive price: Base = Total / (1 + GST Rate/100).

For intra-state (same state) transactions, GST is split equally between CGST (Central GST) and SGST (State GST). For inter-state transactions, IGST (Integrated GST) applies at the full rate.

India has 5 GST rate slabs: 0% (essential goods), 5% (basic necessities), 12% (standard goods), 18% (most goods and services), and 28% (luxury/sin goods).

If you have the GST-inclusive price, divide by (1 + GST Rate/100) to get the base price. For example, Rs 118 at 18% GST: 118 / 1.18 = Rs 100 base price.

The 28% slab applies to luxury and sin goods: cars and two-wheelers above certain engine capacity, tobacco, aerated drinks, air conditioners, digital cameras, and goods covered under the Compensation Cess. Many items that were originally at 28% have since been moved to 18% by GST Council revisions.

Composition scheme dealers (turnover below Rs 1.5 crore) pay GST at reduced flat rates — 1% for traders, 5% for restaurants, 6% for service providers — instead of the standard slab rates. Composition dealers cannot issue tax invoices or charge GST separately from customers. This calculator uses standard slab rates, not composition rates.

GST is calculated on the net taxable value after deducting any pre-agreed discounts that are mentioned on the invoice. Post-sale discounts are handled through credit notes. Enter the post-discount price as the base amount in this calculator to get the correct GST on a discounted transaction.