GST Calculator not working? Here's how to fix it
Most issues with the GST Calculator are small and fixable in seconds. Work through these in order.
1. The tool won't load
Reload the page or open it in a fresh tab. If an extension blocks scripts, try private (incognito) mode — the calculator needs JavaScript, which is on by default in every modern browser.
2. The GST amount is going the wrong way
Check the mode. If you entered an exclusive price but the tool treated it as inclusive, the GST will appear to be subtracted instead of added. Confirm you picked the correct direction first.
3. The number is too high or too low
Check the slab rate. Indian GST applies at 5%, 12%, 18%, or 28%. If the rate is wrong, the whole amount changes. Verify the correct slab for the goods or service you are checking.
4. The breakdown does not match a printed bill
Bills sometimes round the total to the nearest rupee or combine CGST and SGST on a different basis. Compare the base price rather than the rounded total — the tool shows the exact pre-rounding figure.
5. You entered a price that already includes GST
If the price on a label already includes tax, use inclusive mode. Entering an MRP into exclusive mode will double-charge GST. Switch the mode and redo the calculation.
Verdict
Nine out of ten issues with the GST Calculator are solved by confirming the mode (inclusive or exclusive) and the correct slab rate.