How is GST calculated on an exclusive amount?

To calculate GST on an exclusive amount: multiply the net base amount by the GST rate percentage and divide by 100. Add that result to the net base amount to obtain the final invoice total: GST Amount = (Base Price × Rate) ÷ 100; Total Price = Base Price + GST Amount.

How do you extract the GST amount from an inclusive price?

To reverse-calculate GST from an inclusive retail tag: divide the total price by (1 + GST Rate ÷ 100) to find the pre-tax base amount. Subtract the base amount from the total price to find the exact tax component: GST Amount = Total Price - [Total Price ÷ (1 + GST% ÷ 100)].

What are the official GST tax slabs in India?

The primary tax slabs are 0% (exempt essential food grains, milk, fresh vegetables), 5% (packaged staples, medicines, transport), 12% (processed food, computers), 18% (most commercial services, industrial goods), and 28% (luxury automobiles, aerated drinks, high-end electronics).

Tax & Invoicing Calculation Engine

GST Calculator

Q: What is the difference between GST inclusive and GST exclusive amounts?

GST exclusive means the price shown is the net baseline cost before adding tax (GST is added on top: Total = Base + Tax). GST inclusive means the final retail price already incorporates the tax portion (Base = Total ÷ (1 + Tax Rate / 100)).

Q: What is the difference between CGST, SGST, and IGST?

For intra-state transactions (buyer and seller within the same state), GST is split equally into Central GST (CGST) and State GST (SGST), such as 9% CGST + 9% SGST for an 18% slab. For inter-state sales (across state borders) or imports, Integrated GST (IGST) is levied at the full rate (18%).

Calculate Goods & Services Tax for inclusive or exclusive amounts with CGST, SGST, and IGST breakdowns.

Calculation Type

Supply Transaction Type

Net Amount (Before Tax)

₹

Base price without GST included

GST Tax Rate (%) 18% Standard

Select preset slab or enter custom rate

Official GST Slabs Tap to apply rate

Final Gross Invoice Amount

₹11,800.00 +₹1,800.00 GST (18%)

Net Base Price ₹10,000.00 with 18% GST added

Base Pre-Tax Price ₹10,000.00 Net price

Total GST Amount ₹1,800.00 18.0% total tax

CGST (Central) ₹900.00 9.0% share

SGST (State) ₹900.00 9.0% share

Net Product Value: 84.7% Total Tax Component: 15.3%

Comparative GST Breakdown for Current Input: All standard slabs

Tax Slab	Base Price	GST Tax	CGST / SGST	Total Invoice

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Taxation Mechanics & Invoicing Rules

About the Goods and Services Tax (GST) Calculator

The Goods and Services Tax (GST) is a unified, multi-stage destination-based indirect tax levied on the sale of goods and services. Whether you are generating business-to-business (B2B) tax invoices, calculating consumer retail billing, or verifying vendor purchase orders, understanding how to apply tax on exclusive amounts or strip tax from inclusive amounts prevents costly accounting discrepancies.

1. GST Exclusive Formula (Add GST)

GST Amount = (Net Price × GST Rate) ÷ 100
Gross Price = Net Price + GST Amount

Used when quote prices represent baseline merchandise value and statutory tax must be charged on top.

2. GST Inclusive Formula (Reverse Extract)

Net Price = Gross Price ÷ (1 + GST Rate ÷ 100)
GST Amount = Gross Price - Net Price

Used to extract the underlying product cost and exact tax paid from maximum retail price (MRP) shelf tags.

Understanding Tax Structure: Intra-State vs. Inter-State

Intra-State Supply (Within Same State): Revenue is divided equally between the Central Government (CGST = Rate ÷ 2) and the State Government (SGST = Rate ÷ 2). For an 18% item, 9% goes to CGST and 9% to SGST.
Inter-State Supply (Across State Borders or Imports): The entire tax is collected as Integrated GST (IGST = Full Rate) by the Central Government and apportioned to the destination consumption state.
Input Tax Credit (ITC): Registered businesses can offset GST paid on inward commercial purchases against GST liability collected on outward sales, preventing cascading tax-on-tax inflation.

Frequently Asked Questions

What is the difference between GST inclusive and GST exclusive amounts?

GST Exclusive means the quoted price is the net product cost without any tax. GST is added on top when creating the invoice (Total = Price + Tax). GST Inclusive means the advertised price (such as an MRP shelf price) already contains all taxes. To find the pre-tax base cost, you reverse-calculate the tax out (Base = Total ÷ (1 + Tax% ÷ 100)).

How is GST calculated on an exclusive net amount?

Multiply your pre-tax base cost by the tax rate percentage, then divide by 100 to get the GST amount. Add this tax to your base price to find the total customer invoice:
GST = (Base × Rate) ÷ 100
Total = Base + GST
For example, a ₹10,000 base item at 18% GST yields ₹1,800 tax, resulting in a ₹11,800 final billing total.

How do you extract the GST amount from an inclusive total price?

Do not simply multiply the gross price by the tax rate, as this overcharges the tax. Instead, divide the gross amount by 1 plus the tax decimal to discover the true base price, then subtract:
Base Price = Gross Total ÷ [1 + (Rate ÷ 100)]
GST Paid = Gross Total - Base Price
For a ₹1,180 inclusive product at 18%: Base = ₹1,180 ÷ 1.18 = ₹1,000, and GST is ₹180.

What is the difference between CGST, SGST, and IGST?

CGST (Central GST) and SGST (State GST) apply to intra-state trade (where both supplier and customer reside within the same state boundaries). The total rate is divided 50/50 between the Center and the State. IGST (Integrated GST) applies when shipping goods across different states or importing internationally; the full rate is charged under IGST and remitted to the Central Government.

Is my accounting, billing, or client tax data stored on any server?

Never. All arithmetic and tax breakdowns execute 100% locally on your personal device using client-side JavaScript. None of your invoice numbers, billing figures, or client transaction amounts are transmitted across servers or recorded in databases.