GST / Sales Tax Calculator Online

Calculate Goods and Services Tax (GST) and sales tax. Easily calculate GST inclusive and GST exclusive amounts, tax breakdowns, CGST, and SGST.

Input Parameters

Currency:

Calculation Result

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Enter values to see real-time calculation.

About GST / Sales Tax Calculator

Goods and Services Tax (GST) and value-added sales taxes are standard consumption taxes levied on goods and services in major global economies including India, Australia, Canada, the UK (VAT), and New Zealand. Navigating tax calculations for invoicing, purchasing, and business accounting requires accurately computing both Inclusive and Exclusive rates.

* **GST Exclusive (Add GST)**: Calculates the tax amount and gross total when starting from the net base price.
* **GST Inclusive (Remove GST)**: Back-calculates the net base price and extracted tax from a gross amount that already has tax included.

Our tool supports both standard tax slabs (0%, 5%, 12%, 18%, 28%) and custom tax rates with an automatic CGST/SGST 50-50 bifurcation.

Mathematical Formula & Calculation Method

📐 Calculation Formula

GST Exclusive: Total = Net × (1 + Rate/100) | GST Inclusive: Base = Gross / (1 + Rate/100)

For GST Exclusive, multiply the net base amount by the tax rate percentage to find the GST amount, then add it to the base. For GST Inclusive, divide the total price by (1 + Tax Rate / 100) to find the original pre-tax base price, then subtract the base price from the total to find the included tax.

Variable	Definition / Parameter	Unit
`Net Amount`	Pre-tax base price of the item or service	Currency
`GST Rate`	Applicable tax percentage rate (e.g., 5%, 12%, 18%)	%
`GST Amount`	Total tax currency value payable	Currency
`Gross Total`	Final invoice amount inclusive of all taxes	Currency

Step-by-Step Calculation Examples

Example #1

Adding 18% GST to an Invoice ($1,000 Net Base)

Scenario: You are billing a client $1,000 for consulting services with 18% GST.

Given Inputs:

Net Base Price: $1,000.00
GST Rate: 18%
Mode: Exclusive (Add Tax)

Working: GST = ($1,000 × 18) / 100 = $180.00 | Gross = $1,000 + $180 = $1,180.00

Calculated Result: Base: $1,000.00 | GST: $180.00 (CGST $90 + SGST $90) | Total: $1,180.00

Example #2

Extracting 12% GST from a Retail Receipt ($560 Total)

Scenario: You purchased an item for $560 including 12% sales tax and need the pre-tax base cost.

Given Inputs:

Gross Amount: $560.00
GST Rate: 12%
Mode: Inclusive (Remove Tax)

Working: Base = $560 / (1 + 0.12) = $560 / 1.12 = $500.00 | GST = $560 - $500 = $60.00

Calculated Result: Pre-Tax Base: $500.00 | Extracted Tax: $60.00

How to Use the GST / Sales Tax Calculator

Enter the initial monetary amount.
Select a preset GST rate (5%, 12%, 18%, 28%) or enter a custom rate.
Choose whether to "Add GST" (Exclusive) or "Remove GST" (Inclusive).
Instantly review the Net Amount, Tax Amount, CGST/SGST split, and Final Gross Total.

Common Real-World Use Cases

Freelancers & Contractors

Generate compliant quotes and client invoices with accurate line-item tax additions.

Retail & E-commerce Sellers

Determine base manufacturing margins when selling products at all-inclusive retail price points.

Business Expense Accounting

Extract input tax credits (ITC) from vendor receipts and restaurant bills.

Key Features & Capabilities

Bifurcated tax breakdown showing Central GST (CGST) and State GST (SGST).
Supports both Add GST (Exclusive) and Remove GST (Inclusive) modes.
Custom percentage support for international VAT / HST / PST rates.
Instant clipboard copy of calculation summaries.

Technical Architecture & Privacy

GST / Sales Tax Calculator is engineered with a focus on performance, mathematical accuracy, and maximum user privacy. Operating entirely in-browser on the client side, all processing takes place locally within your browser's JavaScript engine. None of your financial numbers, text entries, or private inputs are ever transmitted to or stored on remote servers.

Frequently Asked Questions

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

GST exclusive means the tax is added onto the base price. GST inclusive means the listed sticker price already contains the tax amount.

How do I calculate 18% GST backwards? ▾

Divide the total inclusive price by 1.18. The result is the pre-tax base price. Subtract this base price from the total to get the exact 18% tax amount.

What are CGST and SGST? ▾

Under dual GST structures (like India), intra-state transactions split the tax equally between Central GST (CGST) and State GST (SGST). For an 18% rate, 9% goes to CGST and 9% to SGST.