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OnePlaceTool

GST Calculator

Add GST to a price or take it out of one.

Your files stay on your device

What is this amount?
GST rate
Where is the sale going?
Amount before GST
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GST
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Total payable
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How the GST splits

CGST (central) -

SGST / UTGST (state) -

How to use GST Calculator

  1. Enter the amount you are working from.
  2. Say whether that amount is before GST or already includes it. Getting this the wrong way round is the most common mistake.
  3. Pick the GST rate, or type an exact one if your item sits at an unusual slab.
  4. Choose whether the sale stays inside your state or goes to another one, which sets the CGST and SGST or IGST split.
  5. Read the base, the tax and the total. Everything updates as you type.

How GST is worked out

Adding GST is plain multiplication: GST = amount × rate ÷ 100. Removing it is where people go wrong. To take 18% out of a GST-inclusive ₹11,800 you divide instead of subtracting: base = 11,800 ÷ 1.18 = ₹10,000. Subtracting 18% of ₹11,800 would give ₹9,676 and leave your books short.

CGST, SGST and IGST

The rate is the same either way. Only the split changes. A sale inside one state divides the tax equally between the centre and the state, so 18% becomes 9% CGST and 9% SGST. A sale to another state is charged as a single 18% IGST. Union territories use UTGST in place of SGST at the same rate.

A worked example

You quote ₹10,000 for work done for a client in your own state, at 18%. The tax is ₹1,800, split as ₹900 CGST and ₹900 SGST, and the invoice total is ₹11,800. Bill the same client in another state and it is ₹1,800 of IGST instead. The client pays the same ₹11,800.

Limits worth knowing

  • The slabs are 0%, 0.25%, 3%, 5%, 12%, 18% and 28%. Which one applies depends on the HSN or SAC code of what you are selling, and this tool does not try to guess it.
  • Cess on items such as tobacco, aerated drinks and larger cars is charged on top of GST and is not included here.
  • Composition scheme rates, reverse charge and TCS all work differently and are out of scope.
  • The figures help you quote and check an invoice. They do not replace your accountant or the GST portal.

Frequently asked questions

How do I remove GST from a price that already includes it?

Divide, do not subtract. To take 18% out of Rs 11,800 the sum is 11,800 / 1.18 = Rs 10,000. Subtracting would give Rs 9,676 and leave your invoice short. Switch the tool to "GST included" and it does this for you.

What is the difference between CGST, SGST and IGST?

Same tax, split differently. A sale inside one state is divided equally between the centre and the state, so 18% becomes 9% plus 9%. A sale to another state is charged as a single 18% IGST. The customer pays the same either way.

Which GST rate applies to what I sell?

That depends on your HSN code for goods or SAC code for services, which this tool cannot guess. Most services sit at 18%, many essentials at 5% or nil, and luxury items at 28%. Check your code on the GST portal.

Does this include cess?

No. Compensation cess on tobacco, aerated drinks, coal and larger cars is charged on top of GST at its own rate, and it varies by item. Add it separately if it applies to you.

Is the figure here good enough for an invoice?

The arithmetic is exact, so it will match your accounting software at the same rate. What the tool cannot confirm is the rate, your place of supply, or whether reverse charge applies.