# GST Reverse Calculator

> To remove GST from an inclusive price, divide by (1 + rate). For 18% GST, base price = total ÷ 1.18 and GST = total − base. Taking 18% of the inclusive price overstates the base value — a common error on bills and in expense claims.

Interactive calculator: https://www.industax.com/calculators/gst-reverse

- **Base price formula:** Total × 100 ÷ (100 + rate)
- **GST in ₹1,180 at 18%:** ₹180
- **GST in ₹1,050 at 5%:** ₹50

## Divisors for each rate

| GST rate | Divide inclusive price by | GST share of the inclusive price |
| --- | --- | --- |
| 5% | 1.05 | 4.76% |
| 18% | 1.18 | 15.25% |
| 40% | 1.40 | 28.57% |
| 3% | 1.03 | 2.91% |

## When you need reverse calculation

- MRP or quoted prices that include GST
- Splitting a lump-sum contract value into taxable value and tax
- Checking input tax credit on a bill that shows only the total
- Recording restaurant or travel bills in the books

## Worked example: ₹59,000 inclusive quote at 18%

1. Base price = ₹59,000 ÷ 1.18 = ₹50,000.
2. GST = ₹59,000 − ₹50,000 = ₹9,000 (CGST ₹4,500 + SGST ₹4,500).

**Result:** Taxable value ₹50,000 and GST ₹9,000.

## FAQs

### Why isn't GST just 18% of the total?

Because the total already includes the tax. 18% of ₹1,180 is ₹212.40, but the GST inside ₹1,180 is only ₹180 — the tax is 18% of the base, not of the total.

### Is MRP inclusive of GST?

Yes. Under legal metrology rules, MRP on packaged goods is inclusive of all taxes, so the GST must be worked out backwards from it.

### Can I claim input tax credit on an inclusive bill?

Only if it is a proper tax invoice showing your GSTIN and the tax separately, and the supplier reports it so it appears in your GSTR-2B.

## Official sources

- GST portal: https://www.gst.gov.in/

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Canonical page: https://www.industax.com/calculators/gst-reverse
Publisher: Indus Tax — CA-led tax and compliance firm (https://www.industax.com). Contact: info@industax.com, 9059139258.
This is general information, not advice for your specific facts.