5%
Essential goods and services
Packaged food, household goods, transport services, economy hotels, small restaurants. Common for kirana stores and daily-use retail.
Free tool for Indian businesses
GST Calculator Online for Indian Businesses
Calculate GST amount, CGST, SGST and total price for any amount and rate — instantly. Supports GST-exclusive and GST-inclusive amounts.
All GST rates — 5%, 12%, 18%, 28%
CGST + SGST breakup
Inclusive & exclusive modes
How to use
Enter the amount, choose the GST rate, and select whether your amount already includes GST or not. Results update as you type.
Base Amount—
CGST (2.5%)—
SGST (2.5%)—
Total GST—
Total Amount—
Want GST calculated automatically on every invoice? Try Ledgerly free — set GST rate per product once and it applies automatically with CGST/SGST breakup on every bill.
GST Rate Reference
Common GST rates for Indian small businesses
12%
Processed goods
Processed food, mobile phones, computers, business class travel, certain construction services. Common for electronics and mobile shops.
18%
Most goods and services
Capital goods, most manufactured products, financial services, restaurants, IT services. Covers the largest category of goods traded by small businesses.
How it works
What is a GST calculator and how to use it
A GST calculator helps you quickly calculate the GST amount, taxable value, CGST, SGST, IGST and final invoice value for any transaction. Instead of doing the maths manually each time, you enter the amount and GST rate and get the full breakdown instantly.
Shop owners, traders, wholesalers and service providers use GST calculators to prepare quotations, verify supplier bills, check invoice values and confirm GST breakups before sharing bills with customers.
How to use this GST calculator
- Enter the amount in the Amount field
- Select the GST rate — 5%, 12%, 18% or 28%
- Choose whether your amount is GST-exclusive or GST-inclusive
- Select same-state (CGST + SGST) or interstate (IGST)
- The taxable value, GST amount and final total appear instantly
GST Exclusive Formula
GST Amount = Amount × GST Rate ÷ 100
Total = Amount + GST Amount
Total = Amount + GST Amount
Example: Item value ₹1,000 at 18% GST → GST = ₹180 → Total = ₹1,180
GST Inclusive Formula
Base Amount = Total × 100 ÷ (100 + GST Rate)
GST Amount = Total − Base Amount
GST Amount = Total − Base Amount
Example: Price including GST ₹1,180 at 18% → Base = ₹1,000 → GST = ₹180
CGST, SGST and IGST
Understanding GST components for Indian businesses
GST in India is collected as two components for intra-state sales and one component for inter-state sales. Understanding the difference is important for correct invoicing.
CGST
Central GST
Collected by the central government on sales within the same state. For 18% GST, CGST = 9%.
SGST
State GST
Collected by the state government on same-state sales. For 18% GST, SGST = 9%. Always equal to CGST.
IGST
Integrated GST
Applied on inter-state sales. For 18% GST, IGST = 18% — the full rate applies as one component.
FAQs
Frequently asked questions about GST calculation
What is a GST calculator?
A GST calculator helps you calculate the GST amount, taxable value, CGST, SGST, IGST and final invoice total for any product or service based on the applicable GST rate. It saves time compared to manual calculation and reduces errors on invoices.
How do I calculate 18% GST on ₹1,000?
GST amount = ₹1,000 × 18 ÷ 100 = ₹180. Final invoice value = ₹1,180. For same-state sale: CGST = ₹90, SGST = ₹90. For interstate sale: IGST = ₹180.
What is the difference between GST inclusive and exclusive?
GST exclusive means GST is added on top of the price (base price + GST = final). GST inclusive means the price already includes GST and you need to extract the base amount from it. Both modes are supported in this calculator.
What is the difference between CGST and SGST?
CGST (Central GST) goes to the central government and SGST (State GST) goes to the state government. Both apply on intra-state sales and are always equal. For 18% GST, CGST = 9% and SGST = 9%.
When is IGST used instead of CGST and SGST?
IGST (Integrated GST) is used when goods or services are sold from one state to another. The full GST rate applies as a single IGST component instead of being split between CGST and SGST.
Which GST rate applies to my product?
GST rates are determined by the HSN code of the product or SAC code of the service. Common rates are 0%, 5%, 12%, 18% and 28%. Verify the applicable rate for your product with your accountant or official GST source. Use the HSN/SAC Code Finder to look up codes.
Can I use this calculator to verify supplier bills?
Yes. Enter the total amount from the supplier bill, select the GST rate and choose GST-inclusive mode. The calculator will show the taxable base amount and GST breakdown for verification.
Can GST be calculated automatically on invoices?
Yes. With the Ledgerly GST Billing App, you set the GST rate per product once and it applies automatically on every invoice with CGST/SGST breakup — no manual calculation needed.
Automate GST calculation on every invoice with Ledgerly
Set GST rate per product once. Ledgerly calculates CGST, SGST and totals automatically on every bill — no manual calculation needed.
- GST rate stored per product — applies on every invoice automatically
- CGST and SGST breakup printed on every GST invoice
- PDF invoice ready to share on WhatsApp instantly
More free tools
Other calculators and tools for Indian small businesses.