MSMuhammad Shahid

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GST calculator

Add GST to a net price or take it out of a total, at any rate, with the Indian CGST and SGST split.

Rates vary by country and product and can change, so confirm yours with your tax authority or accountant.

Quick answer

To add GST: multiply the amount by the rate ÷ 100 and add it, so 1,000 at 18% is 180 GST and 1,180 in total. To remove GST: divide the total by (1 + rate ÷ 100), so 1,180 ÷ 1.18 is 1,000 before tax. In India, GST within a state splits equally into CGST and SGST; between states, the full amount is IGST.

How to use it

  1. Enter the amount. Use the price before tax, or the total if it already includes GST.
  2. Set the rate. Press a common rate or type your own.
  3. Add or remove. Choose the direction to see the net amount, the GST and the total.

Example

Adding 18% GST to 1,000, then taking it back out of 1,180:

Input

Add: 1,000 at 18%
Remove: 1,180 at 18%

Output

GST: 180.00, Total: 1,180.00
CGST: 90.00, SGST: 90.00
Net amount: 1,000.00, GST: 180.00

Common errors and how to fix them

The tax I removed is too high
You took a percentage of the total. Choose "Remove GST from the amount", which divides by (1 + rate ÷ 100).
My invoice differs by a small amount
Invoices often round each line or the total to two decimals or a whole rupee. A difference of a few paise is normal.

Frequently asked questions

What is the formula for GST?

Adding: GST = amount × rate ÷ 100. Removing: net = total ÷ (1 + rate ÷ 100), and GST = total − net.

Why not just take 18% off the total to remove GST?

Because 18% was calculated on the smaller net price. 18% of 1,180 is 212.40, which is too much; the GST inside 1,180 is 180.

What are the GST rates in India?

Since 22 September 2025 the main slabs are 5% and 18%, with 40% on luxury and sin goods, plus special rates such as 3% on gold. The 12% and 28% slabs were folded in for most goods, but stay as buttons for older invoices.

What is the difference between CGST, SGST and IGST?

Within one Indian state, tax is split equally between the centre (CGST) and the state (SGST). For sales between states, the whole amount is IGST.

What is the GST rate in other countries?

As general guides: Australia 10%, New Zealand 15%, Singapore 9%, and Canada 5% federal, with provincial taxes on top. Pakistan's standard sales tax on goods is 18%. Confirm the current rate with your tax authority.

Is GST the same as VAT?

They work the same way: a tax on value added at each stage, paid by the final customer. The name varies by country.

Can I use this for my tax filing?

Use it for quick checks. Rates and rounding rules depend on the product and country, so rely on your accountant or official portal for filings.

Are my figures stored?

No. Everything is calculated in your browser.

How do I work out the price before GST?

Choose "Remove GST from the amount" and enter the total. For a discount on top, use the discount calculator.

Can I use a custom rate?

Yes. Type any rate in the GST rate box. The buttons are only shortcuts for common rates.

Sources

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By Muhammad Shahid. Last updated .