Free Tools
GST Tools
Free calculators and lookup tools for everyday GST tasks. No login, no cost. Built and maintained by Financial Sage.
GST Calculator→
Add or remove GST from any amount, with CGST/SGST split.
Reverse GST Calculator→
Find the base price and GST hidden inside a GST-inclusive amount.
GST Late Fee Calculator→
Estimate the late fee for filing GSTR-1/GSTR-3B after the due date.
GST Interest Calculator→
Estimate interest owed on GST paid after the due date.
HSN/SAC Code Search→
Find the right HSN or SAC code and indicative GST rate for your product or service.
GSTIN Format Validator→
Check whether a GSTIN follows the correct 15-digit format.
GST Due Date Checker→
Look up the next GSTR-1, GSTR-3B, and GSTR-9 due dates.
Looking for income tax calculators? See our income tax tools, including an old-vs-new regime comparison.