GST Inclusive Calculator
You know the final price including GST — find out how much of it is tax.
Enter the tax-inclusive amount to see how much GST is inside it.
How the calculation works
A GST-inclusive amount already contains the tax. The calculator divides by the rate factor to pull the taxable value out first, then derives the tax as the remainder.
- Taxable value
Inclusive amount ÷ (1 + Rate ÷ 100) - Total GST
Inclusive amount − Taxable value - CGST / SGST
Taxable value × (Rate ÷ 2) ÷ 100 each - IGST
Taxable value × Rate ÷ 100
Worked example
You sell a service package billed at ₹11,800 including GST at 18%, intra-state.
You enter
You get
Important points to keep in mind
- Use this when your price list or MRP already includes tax and you need the split for invoicing.
- The taxable value is what you report in your returns — not the inclusive figure.
- For inter-state sales the same total GST appears as IGST instead of two halves.
- Rounding follows normal paise conventions; tiny differences from manual math are usually rounding.
Frequently asked questions
Is an MRP always GST-inclusive?
Under the Legal Metrology rules the printed retail price (MRP) includes all taxes, so yes — treat MRP figures as GST-inclusive amounts.
How do I remove 18% GST from ₹11,800?
Divide by 1.18 rather than subtracting 18%. ₹11,800 ÷ 1.18 gives ₹10,000 as the base, leaving ₹1,800 as GST. Subtracting 18% directly would give the wrong base.
Does this work for reverse charge supplies?
The arithmetic is the same, but for reverse-charge supplies the recipient pays the tax to the government instead of you. Record such invoices separately in your books.
Why doesn't my invoice software match exactly?
Software rounds line-by-line before totalling; this tool works from the final amount. Differences of a few paise are rounding and acceptable on invoices.
Related GST tools
Prepare your returns in GSTSelf
Done estimating? Prepare the actual return.
GSTSelf walks you through your invoices, builds GSTR-1 and GSTR-3B data, and keeps everything on your device — no uploads, no account.