When you only have the tax figure
Sometimes a bill or a bank entry gives you the GST amount and nothing else. Your books need the taxable value it was charged on, and your return needs it split by head. This tool runs that calculation backwards.
The formula
Taxable value = GST amount × 100 ÷ rate
Invoice total = Taxable value + GST amount
CGST = SGST = GST amount ÷ 2 (same-state supply)
Invoice total = Taxable value + GST amount
CGST = SGST = GST amount ÷ 2 (same-state supply)
Worked example
₹1,800 of GST at 18%
- GST amount
- ₹1,800.00
- Taxable value
- ₹10,000.00
- CGST at 9%
- ₹900.00
- SGST at 9%
- ₹900.00
- Invoice total
- ₹11,800.00
Where this comes up
- Reconciling a bank statement against purchase invoices
- Checking whether a vendor charged the rate they claimed
- Reconstructing a taxable value for input tax credit
- Fixing an entry where only the tax column was recorded
If instead you have the inclusive total, the GST Reverse Calculator is the tool you want.
Frequently asked questions
How do I find the taxable value from a GST amount?
Multiply the GST by 100 and divide by the rate. At 18%, ₹1,800 of tax means a taxable value of ₹10,000.
Is this the same as a reverse GST calculation?
No. Reverse GST starts from the inclusive total. This starts from the tax figure alone.
What if the supply is inter-state?
Then the whole amount is IGST and there is no CGST or SGST split. Switch the place of supply to see that.