GST Calculator
Add GST to a price, or remove GST from a GST-inclusive amount, across India's 5%, 12%, 18% and 28% slabs — with the CGST and SGST split shown. Calculated instantly in your browser.
How to calculate GST
To add GST, multiply the base amount by the GST rate and divide by 100 — that's the GST, which you add to the base for the total. To remove GST from a price that already includes it, divide the inclusive amount by (100 + rate) and multiply by 100 to get the base; the difference is the GST. For example, ₹1,180 including 18% GST has a base of ₹1,000 and ₹180 GST.
CGST and SGST
For sales within the same state (intra-state), GST is split equally into CGST (Central GST) and SGST (State GST) — so 18% becomes 9% CGST + 9% SGST. For sales between states (inter-state), the same total is charged as a single IGST instead. The calculator shows the equal split, which also equals the IGST total.
Frequently asked questions
How do I calculate GST on an amount?
Enter the amount and choose a slab (5%, 12%, 18% or 28%) or a custom rate. "Add GST" shows the GST and total; "Remove GST" extracts the base and GST from an inclusive price.
How do I remove GST from a total?
Switch to "Remove GST", enter the GST-inclusive amount, and pick the rate. The base amount is the inclusive total × 100 ÷ (100 + rate); the rest is GST.
What are the GST slabs in India?
The main GST rates are 5%, 12%, 18% and 28%, with some goods at 0% or 3%. Pick the slab that applies, or type a custom rate.
What is the difference between CGST, SGST and IGST?
Within a state, GST splits equally into CGST and SGST. Between states, the same total is charged as IGST. The total tax is the same either way.