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How to Use the GST Calculator: A Step-by-Step Guide

Learn how to add or remove GST from a price in a few steps — inclusive, exclusive, multiple rates, and a clear breakdown.

Published August 28, 20264 min read
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How to use the GST Calculator in a few steps

The GST Calculator is designed so a typical calculation takes under 10 seconds. Follow these steps.

Step 1: Choose inclusive or exclusive

Pick whether your price already includes GST (inclusive) or whether GST should be added on top (exclusive). This determines the direction of the calculation.

Step 2: Enter the amount and rate

Type the base amount and select the applicable GST slab — 5%, 12%, 18%, or 28% on goods and services.

Step 3: Read the breakdown

The result shows the base price, the GST amount, and the final total. If you chose inclusive, the base and GST are worked out from the total; if exclusive, GST is added to the base.

The breakdown updates the moment you change the amount or rate, so you can compare scenarios in seconds.

Using it for billing and checks

  • Use exclusive mode to compute the GST and total for your own invoices
  • Use inclusive mode to pull the base amount out of a supplier bill
  • Compare different slab rates to check which one applies to your goods or service

What you need to get started

Only a modern browser (Chrome, Firefox, Safari, or Edge). There is nothing to install and no account to create.

Verdict

With the GST Calculator you can add or remove GST in one click and see the exact breakdown — free and private.

Free tools to do it now

Frequently asked questions

How long does a GST calculation take?

Instantly. Results appear the moment you enter the amount and rate because the calculation runs locally in your browser.

Can I switch between inclusive and exclusive?

Yes. Toggle the mode and the tool immediately recalculates in the other direction.

What browser do I need?

Any current version of Chrome, Firefox, Safari, or Edge.

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