Free GST Calculator — Tax Slabs, CGST/SGST & Reverse GST
Calculate Indian Goods and Services Tax instantly. Add GST to your base cost or extract pre-tax value from inclusive MRPs across 5%, 12%, 18%, and 28% slabs with exact CGST, SGST, and IGST breakdowns.
GST Breakdown for ₹1,000 at 18%
| Tax Component | Applicable Rate | Calculated Amount |
|---|---|---|
| Base Value (Taxable Amount) | — | ₹1,000 |
| CGST (Central Goods & Services Tax) | 9% | ₹90 |
| SGST (State Goods & Services Tax) | 9% | ₹90 |
| Total Bill Value (Gross) | 18% Total | ₹1,180 |
Tired of calculating GST manually for every customer?
Karobari automatically applies 0%, 5%, 12%, 18%, or 28% GST to your item catalogue, prints HSN codes on thermal receipts, and exports accountant-ready CSV files — 100% free with zero subscription fees.
How Indian GST is calculated at the counter
Indian GST calculations follow two distinct mathematical models depending on whether your price is exclusive or inclusive of taxes.
1. GST Exclusive (Add GST)
Used when wholesale rates or supplier base costs do not yet include tax. You add GST on top of the taxable base amount to arrive at the total payable price.
Total Price = Base Price + GST Amount
2. GST Inclusive (Reverse GST)
Used for packaged consumer goods where the shelf price (MRP) already includes tax. The formula removes the tax portion to discover actual taxable base earnings.
GST Amount = Total MRP - Base Price
Indian GST tax slabs by retail trade
A quick reference guide for retail shopkeepers and mart owners across major product categories.
| Tax Slab | Intra-State Split | Inter-State Rate | Common Retail Goods |
|---|---|---|---|
| 0% (Exempt) | 0% CGST + 0% SGST | 0% IGST | Fresh milk, fruits, unbranded flour, eggs, salt, bread |
| 5% | 2.5% CGST + 2.5% SGST | 5% IGST | Packaged edible oil, sugar, tea, coffee, spices, sweets (mithai) |
| 12% | 6% CGST + 6% SGST | 12% IGST | Essential medicines, computers, processed food, apparel over ₹1,000 |
| 18% (Standard) | 9% CGST + 9% SGST | 18% IGST | Hair oil, soaps, toothpaste, electronics, retail software, services |
| 28% | 14% CGST + 14% SGST | 28% IGST | Air conditioners, automobiles, luxury goods, aerated cold drinks |
Common questions about Indian GST calculations
How is GST calculated on a retail price (Exclusive vs Inclusive)?
For GST Exclusive (Add GST): GST Amount = (Base Price × GST Rate) / 100, and Total Price = Base Price + GST Amount. For GST Inclusive (Reverse GST): Base Price = Total Price / (1 + GST Rate / 100), and GST Amount = Total Price - Base Price.
What is the difference between CGST, SGST, and IGST?
When a sale occurs within the same state (Intra-State), the tax is split equally between CGST (Central Goods and Services Tax) and SGST (State Goods and Services Tax). When goods or services are sold to another state (Inter-State), 100% of the tax is levied as IGST (Integrated Goods and Services Tax).
What are the standard GST tax slabs in India?
India operates primarily under four GST tax slabs: 5% (packaged food, tea, spices), 12% (medicines, computers, apparel over ₹1,000), 18% (electronics, soaps, retail software, standard services), and 28% (luxury items, automotive, air conditioners). Fresh food and milk are in the 0% exempt category.
Does the Karobari billing app calculate GST automatically at the counter?
Yes. In Karobari, you can assign 0%, 5%, 12%, 18%, or 28% GST to any item in your catalog. When ringing up customer bills, the app computes CGST, SGST, and HSN codes automatically with zero manual calculation, printing clean compliant receipts.