Seller ProfitGST inclusive and exclusive price calculator
Take the GST out of a price that includes it, or add it to a price that does not, without the common mistake of subtracting the percentage.
The formulas
- Price with GST = price without GST x (1 + rate / 100).
- Price without GST = price with GST / (1 + rate / 100).
- GST amount = price with GST minus price without GST.
Worked example
At a rate of 18 percent, a price of 1,180 with GST contains a price of 1,000 without GST and 180 of GST. Taking 18 percent off 1,180 would give 967.60, which is wrong by 32.40 on one sale.
Why sellers need this
Your sale value, for the purpose of margin, is the price without GST. Marketplace fees may be charged on the price with or without GST, and your cost may or may not include GST that you can claim back. Each choice changes the margin, which is why the profit calculator asks about all of them. Ask the tax authority or an accountant which GST rate applies to your product and whether you can claim credit; this site does not state rates.
Common questions
Why not just subtract 18 percent from a price with 18 percent GST?
Because GST is charged on the price without GST. A price of 118 includes 18 of GST, which is 18 divided by 118, about 15.3 percent of the price, not 18 percent.
Do I have to show GST separately?
That depends on your registration and your country. Ask your tax adviser. The calculator only does the arithmetic.
Keep going
Fee percentages, GST rates and other figures in the examples on this site are made up to show the working. They are not the fees or rates of any marketplace or country: type the numbers from your own seller account and from the tax authority. Checked 14 November 2026.