GST calculator
Put GST on top of a price, or pull out the GST already sitting inside one. Both directions, with the CGST and SGST split a tax invoice has to show.
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Add GST or take it back out
Taking GST out is not the same as taking the rate off
This is the mistake that quietly costs money. A customer pays ₹1,180 including 18% GST, and the obvious move is to knock 18% off ₹1,180 — ₹212.40 — and call the rest your sale. It isn't. The tax was charged on ₹1,000, so the GST inside that price is ₹180, and the base is ₹1,000. The formula is the amount divided by 1.18, not multiplied by 0.82.
The gap grows with the rate. At 28% the wrong method overstates the tax by more than ₹60 on every ₹1,000 of sale, which is enough to distort a month of accounts.
CGST, SGST and IGST are one tax, split three ways
The total never changes. Sell within your own state and the tax splits in half: CGST to the centre, SGST to the state, each at half the rate. Sell across a state border and the same total goes over as a single IGST line. An 18% invoice is either 9% + 9% or a flat 18% depending on where the buyer is, and the invoice has to show whichever one applies.
GST is not revenue
What you collect is held on behalf of the government and paid over when you file, less the input credit on your own purchases. It passes through the business; it never belongs to it. Work out margins on the figures excluding GST, or a good month on paper can be a bad one in the bank.
Frequently asked questions
How do I remove GST from a price that already includes it?
Divide by one plus the rate, not by subtracting the rate. At 18%, a ₹1,180 inclusive price is ₹1,180 ÷ 1.18 = ₹1,000 base plus ₹180 tax. Taking 18% off ₹1,180 instead gives ₹212.40, which is wrong by ₹32.40.
What is the difference between CGST, SGST and IGST?
The total tax is the same either way. For a sale inside your own state it is split half as CGST to the centre and half as SGST to the state. For a sale to another state it is charged as one line of IGST at the full rate.
Which GST rate applies to my product?
The rate follows the HSN or SAC code of what you are selling, not your business type. Most goods fall in 5%, 12%, 18% or 28%, with essentials at nil. Check the code for your item on the CBIC rate finder rather than assuming a rate.
Do I charge GST if I am not registered?
No. Only a registered dealer may collect GST and issue a tax invoice. Registration is compulsory past the turnover threshold for your state and category, and voluntary below it.
Is the GST I collect part of my profit?
No. It is collected on behalf of the government and paid over at filing, less the input credit on your own purchases. Margin should always be worked out on the figures excluding GST.