GST Calculator
Compute Goods and Services Tax (GST) inclusive and exclusive amounts with CGST, SGST, and IGST breakdowns.
Tax Parameters
GST Breakdown
About the GST Calculator
The Goods and Services Tax (GST) is a unified, destination-based indirect consumption tax levied on the supply of goods and services. Understanding whether a quoted price is inclusive or exclusive of GST is critical for pricing products, billing clients, claiming input tax credits (ITC), and maintaining transparent accounting.
Our interactive GST calculator simplifies both inclusive and exclusive calculations. Exclusive mode adds GST on top of your net base cost to establish final invoice price. Inclusive mode strips embedded GST out of the gross retail amount to determine pre-tax price and total government remittance.
For domestic intra-state transactions, GST is divided equally into Central GST (CGST) and State GST (SGST). For inter-state transactions, Integrated GST (IGST) is applied in full. This tool computes both allocations instantly across all standard tax slabs (0%, 5%, 12%, 18%, 28%) and custom tax rates.
How the Calculations Work
GST calculations depend on whether you are adding tax to a net base amount or extracting tax from an inclusive price.
GST Exclusive: Tax = Net * (Rate / 100), Gross = Net + Tax | GST Inclusive: Net = Gross / (1 + Rate / 100), Tax = Gross - Net
Variables & Definitions
- Net: Base amount before tax (pre-tax cost)
- Gross: Final total transaction amount including tax
- Rate: GST percentage rate (e.g. 5%, 12%, 18%, 28%)
- CGST / SGST: Central & State tax components (Tax / 2 for intra-state sales)
- IGST: Integrated GST (Full tax amount for inter-state sales)
For a net product cost of ₹10,000 at an 18% GST rate: GST Amount = ₹10,000 * 0.18 = ₹1,800. Final Gross Price = ₹11,800. CGST is ₹900 (9%) and SGST is ₹900 (9%). Conversely, if a retail price is ₹11,800 inclusive of 18% GST: Net Base = ₹11,800 / 1.18 = ₹10,000 and GST = ₹1,800.
Key Terms Explained
GST Inclusive
A pricing model where the quoted sticker price already incorporates all applicable goods and services taxes.
GST Exclusive
A pricing model where the stated price represents the pre-tax base cost, and GST must be added on top at billing.
CGST & SGST
Central Goods & Services Tax and State Goods & Services Tax, split 50/50 on sales made within the same state.
IGST
Integrated Goods & Services Tax, collected by the Central Government on commerce between different states or imports.
Practical Tips & Pitfalls to Avoid
Never apply GST percentage backwards
Taking 18% off an inclusive price overstates the tax. Always divide by (1 + Rate/100) to find the correct base cost.
Verify HSN/SAC classification codes
Different goods and services fall under distinct tax brackets. Always confirm whether 5%, 12%, 18%, or 28% applies to your specific item.
Track Input Tax Credit (ITC)
Business purchasers registered under GST can offset the GST paid on purchases against their GST collected on sales.
Check invoice threshold requirements
Ensure mandatory e-invoicing and digital QR code requirements are satisfied if your annual business turnover exceeds regulatory thresholds.
Frequently Asked Questions
To add GST: Multiply the base amount by (1 + GST Rate / 100). For example, ₹5,000 with 18% GST is ₹5,000 * 1.18 = ₹5,900.
To remove GST: Divide the inclusive total by (1 + GST Rate / 100). The difference between the gross total and this net result is your exact GST amount.
CGST and SGST apply to intra-state sales and split tax revenue equally between Central and State governments. IGST applies to inter-state sales and is remitted to the Central Government.
The standard GST tax rates are 0% (essential foods), 5% (household essentials, transport), 12% (computers, processed foods), 18% (capital goods, IT services), and 28% (luxury items, automobiles).