Reverse Sales Tax Calculator
Enter the price the buyer already paid and your sales tax rate to split the total into the pre-tax price and the tax amount included.
GST, VAT, SST, or sales tax as a percent.
Results
- Price before tax
- 92.59
- Tax amount
- 7.41
- Total (with tax)
- 100.00
Base = inclusive / (1 + rate / 100)
For quotes and checks only. Confirm the correct rate for your location.
Reverse sales tax formula
For sellers quoting GST, VAT, SST, or sales tax inside the number buyers see in chat.
- 01
Enter the full price
The amount the buyer pays, tax already included.
- 02
Enter the tax rate %
Example: 18 for 18% GST, 5 for 5% VAT, 6 for 6% SST.
- 03
Read the split
See the price before tax and how much of the total is tax.
- 04
Use it in the quote
Share the breakdown in WhatsApp when a buyer asks what the tax is.
How to remove sales tax
Buyers often see one number. You still need the base and tax for invoices and your own books.
Answer tax questions fast
When someone asks how much tax is in the quote, you already have the split.
Works with any rate
GST, VAT, SST, or local sales tax. Enter the % you actually charge.
No signup
Calculate in the browser. Nothing to install.
Stays on your device
Prices are not uploaded. The math runs on this page only.
Sales tax formula
Add tax on top, or remove it from a price that already includes it. The last row is the reverse of 18%.
| Price you enter | Rate | Tax | Other side |
|---|---|---|---|
| 100 | 10% | 10 | 110 |
| 100 | 18% | 18 | 118 |
| 100 | 20% | 20 | 120 |
| 118 | 18% removed | 18 | 100 |
Add: tax = price x rate / 100. Remove: base = price / (1 + rate / 100).
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Tax-inclusive questions
How the split works, which rates to use, and how this pairs with Orders App.
What is reverse sales tax?
Working backwards from a price that already includes tax, to find the pre-tax amount and how much of the total is tax.
What is this reverse sales tax calculator?
Enter the price the buyer paid and the rate. It splits that total into the base and the tax.
What does tax-inclusive mean?
The price the buyer pays already includes tax. You need to reverse it to find the pre-tax base and the tax amount.
What is the formula?
Base = inclusive / (1 + rate/100). Tax = inclusive - base. Example: 118 at 18% → base 100, tax 18.
Which tax rate should I enter?
Use the rate that applies to that sale in your country or state. This tool does not pick the rate for you.
Is this legal tax advice?
No. It is simple arithmetic for quotes. Check local rules or an accountant for filing.
Is the tool free?
Yes. No signup. Orders App is separate if you later want DM orders captured into a list automatically.
Get your orders out of your DMs
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