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Money and business

GST calculator (add or remove GST)

Add GST to a price, or find the price before GST inside an amount that already includes it. See the CGST and SGST split for a sale within a state, or IGST between states. You type the rate: check the current rate for your item on the official GST portal.

  • Made forCommerce students, shopkeepers, families
  • Shows the workingEvery step, ready for your practical file
  • Instant answersResults change as you type

Add or remove GST

Type the amount and the GST rate that applies to your item, then choose whether the amount already includes GST.

The amount I have is

Rates are set by the GST Council and change from time to time: check the current rate for your item on the official GST portal.

Supply
Reset

Result

Price including GST₹1,180.00GST at 18% = ₹180.00 (CGST ₹90.00 + SGST ₹90.00)
Price before GST
₹1,000.00
CGST (9%)
₹90.00
SGST (9%)
₹90.00
Total with GST
₹1,180.00

Working

  1. GST = 1,000 × 18 ÷ 100 = ₹180.00.
  2. Total = 1,000 + 180 = ₹1,180.00.
  3. Split equally: CGST = SGST = 180 ÷ 2 = ₹90.00 each (9% each).
  • Check this: This tool does not know any GST rates: it uses the rate you type. Check the current rate and HSN or SAC code for your item on the official GST portal or with a tax professional.
  • Note: Taking GST out is not the same as subtracting 18% of the total: 18% of ₹1,180.00 is ₹212.40, but the GST inside it is ₹180.00.
  • Tip: In union territories without their own legislature the state part is called UTGST instead of SGST.

What it works out

Understanding GST

GST (Goods and Services Tax) is charged on most sales of goods and services in India. On a sale within one state the tax is split equally between the Centre (CGST) and the state (SGST); on a sale from one state to another, the whole tax is IGST.

Shopkeepers, commerce students and anyone checking a bill need two sums: adding GST to a price, and working backwards from a price that already includes it. The second is where most mistakes happen.

Formula and worked example

Working out GST by hand

The calculator uses exactly these formulas. Write them in your notebook and check one answer by hand: it is the surest way to remember them.

The formula

  • Add: GST = price × rate ÷ 100; total = price + GST
  • Remove: price = total × 100 ÷ (100 + rate); GST = total − price
  • Within a state: CGST = SGST = GST ÷ 2 (each at half the rate)
price
the value before GST (₹)
total
the amount including GST (₹)
rate
the GST rate for the item, in %, from the official GST portal

Worked example

A ₹1,180 bill that includes GST (18% used only as an example rate)

  1. Price before GST = 1,180 × 100 ÷ (100 + 18) = 1,18,000 ÷ 118 = ₹1,000.
  2. GST included = 1,180 − 1,000 = ₹180.
  3. Within the same state: CGST ₹90 (9%) + SGST ₹90 (9%).
  4. Note that 18% of ₹1,180 is ₹212.40, which is not the GST inside the bill.

Answer₹1,000 + ₹180 GST (CGST ₹90 + SGST ₹90)

In projects and exams

How students use it

Add GST to a price or take it out, with the CGST and SGST split, at a rate you enter. Here is where it earns its place in a school year.

  • Commerce and accountancy

    Check GST entries and invoice sums in practice questions, with the working shown.

  • Small shop billing

    Find the price to charge, or the tax inside a price, before writing an invoice.

  • Checking a bill

    See how much of a restaurant or shop bill is tax, and how it splits.

  • Tally practice

    Verify the figures your accounting software calculates while you learn it.

Check your work

Common mistakes to avoid

These are the slips that cost marks in exams and burn out parts on the bench.

  1. Taking the rate off an inclusive price

    GST inside ₹1,180 at 18% is ₹180, not 18% of ₹1,180 (₹212.40). Use "Including GST" mode.

  2. Splitting the rate wrongly

    At 18% within a state, CGST and SGST are 9% each, not 18% each.

  3. CGST and SGST on an inter-state sale

    A sale to another state carries IGST at the full rate instead.

  4. Using an old rate

    Rates are revised from time to time. Confirm the current rate for the item's HSN or SAC code before you bill.

Questions

Questions about GST

Stuck on a project or a sum? Ask the institute on WhatsApp.

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What are the current GST rates?

The GST Council sets the rates and revises them from time to time, so this page does not list them. Look up your item's HSN or SAC code on the official GST portal (gst.gov.in) or the CBIC website, or ask a tax professional.

What is the difference between CGST, SGST and IGST?

Within a state, the GST is shared equally between the Centre (CGST) and the state (SGST). On a sale between states it is collected as IGST. In union territories without their own legislature, UTGST takes the place of SGST.

How do I take GST out of an MRP?

An MRP already includes the taxes, so choose "Including GST", type the MRP and the rate, and the calculator shows the price before GST and the tax inside it.

Can I use this to file returns?

It does the arithmetic only. Returns need proper invoices, the correct rates and codes, and often professional advice.

Free ebooks

Read more about GST

Free PDF ebooks in easy English: download, print and share them.

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