Reverse sales tax calculator splits a GST-inclusive amount into base price and tax.
About this calculator
Reverse sales tax calculator splits a GST-inclusive amount into base price and tax. You see this on restaurant bills, Amazon invoices, and expense receipts where only the final total is printed. To claim input tax credit or record expenses correctly, you need the pre-tax figure.
Enter the total you paid and the GST rate (5%, 12%, 18%, or 28% in India). The calculator divides by (1 + rate) to get the taxable value and subtracts to find tax. At 18% intra-state GST, half is CGST and half is SGST.
Use the forward [[gst]] calculator to add tax on top of a base price. For business returns, tie results to [[income-tax]] planning. If the purchase was financed, check [[emi]] impact on cash flow.
Common uses
- Splitting a ₹2,360 restaurant bill at 18% GST for expense report
- Finding taxable value on a GST-inclusive Amazon invoice
- Accountant backing out tax from POS receipt totals
- Freelancer recording pre-tax software subscription cost from inclusive bill
- Verifying vendor invoice before claiming input tax credit
Frequently asked questions
How do I extract 18% GST from a ₹1,180 inclusive bill?
Pre-tax = 1180 ÷ 1.18 = ₹1,000. GST = ₹180. CGST is ₹90 and SGST is ₹90 for intra-state supply. Enter 1180 and 18% here to get the same split instantly.
What is the reverse GST formula for 12% rate?
Pre-tax = Inclusive total ÷ 1.12. On ₹1,120 inclusive, base is ₹1,000 and GST is ₹120. The formula works for any rate: divide by (1 + rate/100).
Does reverse GST work for IGST on inter-state purchases?
Yes for the total tax amount. Inter-state bills show IGST instead of CGST+SGST, but the reverse calculation is identical — total tax equals inclusive minus pre-tax.
Why is my pre-tax amount not matching the MRP on the label?
MRP is the maximum retail price and may already include tax. Discounts apply before or after tax depending on the retailer. Use the actual amount you paid as the inclusive total.