GST Calculator Online Free
Calculate GST for all slabs: 5%, 12%, 18%, and 28%. Supports both GST-inclusive and GST-exclusive calculations.
About this tool
How to calculate GST
Enter an amount, pick a rate, and choose whether GST should be added to your figure or extracted from it. Both directions matter, and confusing them is the most common mistake in GST arithmetic.
Adding versus removing GST
Adding starts from a pre-tax price. At 18%, ₹1,000 becomes ₹1,180, and the ₹180 is the tax you collect and remit.
Removing starts from a price that already includes tax, which is how retail prices are displayed in India. Extracting 18% from ₹1,180 gives a base of ₹1,000 and tax of ₹180. Note that you cannot simply subtract 18% of ₹1,180, because that gives ₹967.60, which is wrong. The correct calculation divides by 1.18, because the tax was charged on the base, not on the total.
The rate slabs
India's GST uses five main rates. 0% covers most fresh food, and educational and healthcare services. 5% applies to essentials, transport and small restaurants. 12% and 18% cover most goods and services, with 18% the most common by far. It is the default for professional services, software and electronics. 28% is reserved for luxury and so-called sin goods, sometimes with an additional cess.
CGST, SGST and IGST
The total is the same either way; only the split changes. A sale within one state divides the tax equally between central GST and state GST, so 18% is 9% CGST plus 9% SGST. A sale across state lines is charged as a single integrated GST of the full 18%, which the centre later apportions. Getting this split wrong on an invoice is a filing problem even when the total is right.
Frequently asked questions
Is the calculation done on my device?
Yes. Nothing is sent anywhere.
Which rate applies to my product?
That depends on its HSN or SAC code. Check the official CBIC rate schedule or ask your accountant. Misclassification is a compliance risk, not a rounding error.
Does this handle cess?
No. Items attracting a compensation cess need that added separately on top.
Are the results suitable for filing?
They are arithmetically correct, but use your accounting software or a professional for actual returns.
Written and maintained by Nudge Systems, Surat
Last reviewed