Finance 5 min read

How to Calculate GST and VAT for Invoices Online

A simple guide to adding or extracting sales tax (GST/VAT) from net or gross invoice prices instantly.

Imaginex AI Finance Team
May 28, 2026

Understanding Indirect Taxes (GST & VAT)

Goods and Services Tax (GST) and Value Added Tax (VAT) are indirect taxes levied on the supply of goods and services. Business owners must apply the correct tax percentages to invoice totals, while buyers often need to calculate base prices by removing tax from gross payments.

Calculate taxes instantly: [GST / Sales Tax Calculator](/tools/gst-calculator).

How to Add GST to Net Price

To calculate the gross price including tax, use this formula:

Gross Price = Net Price + (Net Price x Tax Rate / 100)

How to Extract GST from Gross Price

To determine the net base price and find the tax amount hidden in a total price, use:

Net Price = Gross Price / (1 + Tax Rate / 100)

GST Amount = Gross Price - Net Price

Save time and avoid rounding errors during invoicing. Try our free, offline-ready [GST / Sales Tax Calculator](/tools/gst-calculator).

Tags
gstvatsales taxinvoicingaccounting

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