GST Calculator

Introduction to the GST Calculator

The GST Calculator is a free online tool that finds Goods and Services Tax in both directions using GST Amount = Base Price x GST Rate / 100 and reverse formula Base = Total / (1 + Rate/100). It works across all four Indian GST slabs of 5, 12, 18 and 28 percent.

Indian shopkeepers, freelancers, CA students and B2B suppliers use this GST tool every day for invoices, billing and pricing. Whether you generate a Tally invoice in Surat, raise a freelance bill from Bengaluru or check a restaurant bill in Mumbai, the GST formula stays central. Related concepts like CGST, SGST, IGST, reverse charge and input tax credit all sit on top of this calculation.

Inputs are the base amount, GST slab and supply type (intra-state or inter-state). Outputs are the GST amount, total invoice value and a clean CGST or SGST or IGST split for your books.

Who Should Use This GST Calculator

1. Small kirana store owners in Lucknow raising daily GST invoices for FMCG and grocery deliveries.
2. 2. Freelance designers in Bengaluru billing Indian and overseas clients with correct IGST or zero rated treatment.
3. 3. CA articleship students in Mumbai preparing client GSTR-1 and GSTR-3B filings every month.
4. 4. Restaurant owners in Pune pricing menus to absorb or pass through 5 percent or 18 percent GST.
5. 5. Online resellers in Jaipur reconciling Amazon and Flipkart settlement reports against actual GST payable.

Tips for GST Pricing

Smart GST Tips

1. Always confirm the correct HSN or SAC code before applying a slab, since wrong codes invite GST notices and penalties up to Rs 10,000.
2. 2. For intra-state supply split GST equally into CGST and SGST. For inter-state use full IGST in one line of the invoice.
3. 3. Claim input tax credit only on invoices that show GSTIN, place of supply and signature, to avoid mismatch in GSTR-2B.
4. 4. Round off invoice values to the nearest rupee under section 170 of the CGST Act to keep books tidy.
5. 5. Use composition scheme only if your annual turnover stays below Rs 1.5 crore and you do not need to give input credit.

Formula Explanation

Core GST Formula

GST Amount = Base Price x GST Rate / 100 Total Price = Base Price + GST Amount Reverse Base = Total Price / (1 + Rate / 100) CGST = SGST = GST / 2 (intra-state); IGST = full GST (inter-state)

Where:

• Base Price = price before tax in rupees
• • GST Rate = applicable slab (5, 12, 18 or 28 percent)
• • Total Price = invoice value including tax

Example: A laptop priced at Rs 50,000 with 18 percent GST gives GST = Rs 9000, Total = Rs 59,000. Intra-state breakup is CGST Rs 4500 and SGST Rs 4500.

GST Quick Reference Table

Item Category	GST Slab	Base (Rs)	GST (Rs)	Total (Rs)
Packed snacks	5 percent	100	5	105
Mobile phone	12 percent	15,000	1,800	16,800
Laptop	18 percent	50,000	9,000	59,000
Air conditioner	28 percent	35,000	9,800	44,800
Restaurant bill	5 percent	800	40	840

Real-World Example

Example: Neha's Freelance Invoice

Meet Neha, a 29 year old freelance UI designer from Bengaluru registered under GST since her annual income crossed Rs 20 lakh last year. She is raising a fresh invoice for a Pune startup client.

Step 1: Neha's design fee is Rs 1,00,000 and the slab for design services is 18 percent. Step 2: Since supply is inter-state (Karnataka to Maharashtra), she charges IGST not CGST/SGST. Step 3: GST = 1,00,000 x 18 / 100 = Rs 18,000. Total invoice = Rs 1,18,000.

Result: Neha bills Rs 1,18,000 with IGST Rs 18,000 clearly listed. The client claims input tax credit and Neha pays the Rs 18,000 in her next GSTR-3B return.

Frequently Asked Questions About GST

Indian business owners, shopkeepers and freelancers often have practical questions about GST slabs, CGST/SGST/IGST split and reverse GST extraction. The answers below cover everyday invoicing, input tax credit and composition scheme questions for small Indian businesses.