Quickly calculate forward (add/exclude) and reverse GST amounts for your business transactions in India.
Add or remove GST from a base amount.
Results will be calculated here.
Find the pre-GST value from a total amount.
Results will be calculated here.
Enter your amount, choose the GST rate (5%, 12%, 18%, or 28%), and pick whether the amount is exclusive of GST (you want to add GST) or inclusive (you want to remove GST). The calculator instantly shows the base amount, the GST, and the total, and splits the tax into CGST and SGST for a within-state sale or shows IGST for an inter-state sale.
Forward (add GST): you have the base price and want the final price. Reverse (remove GST): you have the final, GST-inclusive price and want the base price plus the tax hidden inside it. Reverse GST is where most people slip up, because you cannot simply subtract the percentage. The formula is base = amount / (1 + rate/100), and GST = amount - base. This tool does that back-calculation for you.
The standard slabs are 0%, 5%, 12%, 18%, and 28%. 18% is the most common rate for services and software. For a sale within the same state the rate is split into CGST and SGST (half each); for an inter-state sale the whole rate is charged as IGST.
Need to get paid after quoting a price? Create a UPI payment link in seconds, or read the deeper guide on how to add and remove GST in India. Browse all free tools.
It is free, needs no signup, and runs entirely in your browser, so nothing you type is uploaded to a server. It works on your phone and your laptop, and handles both GST-inclusive and GST-exclusive amounts with the CGST, SGST, and IGST split.
