How to Remove GST From an Inclusive Price

To remove GST from an inclusive price, divide the total by 1 plus the GST rate. If Rs. 1,180 includes 18% GST, divide 1,180 by 1.18. The base price is Rs. 1,000 and GST is Rs. 180.

Base price: Base Price = Inclusive Price / (1 + GST Rate / 100)

GST amount: GST Amount = Inclusive Price - Base Price

Inclusive price | GST rate | Base price | GST amount

Rs. 1,050 | 5% | Rs. 1,000 | Rs. 50

Rs. 1,120 | 12% | Rs. 1,000 | Rs. 120

Rs. 1,180 | 18% | Rs. 1,000 | Rs. 180

Rs. 1,280 | 28% | Rs. 1,000 | Rs. 280

Remove GST instantly: Use LinkMitra's GST Calculator to enter an inclusive price and GST rate, then see the base amount and GST amount.

Where reverse GST helps

Checking a supplier bill that already includes GST

Understanding tax inside an all-inclusive quote

Splitting base amount and tax for records

Explaining a GST-inclusive price to a customer

Rounding note: Small rounding differences can appear depending on decimal handling. Review final invoice totals before sharing.

Step-by-step example

Start with inclusive price: Rs. 23,600.

GST rate: 18%.

Divide by 1.18 to get base price: Rs. 20,000.

Subtract base price from inclusive price: Rs. 3,600 GST.

Use base price and GST amount in records if needed.

Reverse GST is useful when a supplier or customer gives only the final price. It helps you understand what portion is base amount and what portion is tax.

Why direct subtraction is wrong

If Rs. 1,180 includes 18% GST, the GST amount is not 18% of 1,180. The 18% applies to the base price, not the inclusive total. That is why you divide by 1.18 first. This is the most common reverse GST mistake in manual calculations.

Use the GST Calculator when checking inclusive prices from supplier bills, customer quotes or final selling prices.

Can I subtract 18% directly from the total?

No. If the price already includes GST, use the reverse formula. Direct subtraction gives the wrong base amount.

Does this tell me the correct GST rate?

No. It only calculates using the rate you enter. Verify the correct rate separately.