What this calculator does
Sales tax, GST and VAT all work the same way arithmetically: a percentage added to a net price. The direction of the calculation is what causes confusion. Adding tax is straightforward; removing it from a tax-inclusive figure requires dividing rather than subtracting the percentage.
That distinction matters in practice. Taking 10% off a tax-inclusive price does not give the net price: it gives a number about 1% too low. This calculator handles both directions, so you choose which one your figure is.
The formula
To add tax, multiply the net price by the tax rate and add it on. To remove tax, divide the gross price by one plus the rate, which recovers the net figure the tax was originally calculated from.
| Term | Meaning |
|---|---|
| Net | The price before tax, sometimes called the ex-tax or exclusive price. |
| Gross | The price including tax, the inclusive price. |
| r | The tax rate as a percentage. |
The inputs explained
| Field | What to enter |
|---|---|
| Amount ($) | The amount you have. |
| Tax rate (%) | The applicable tax rate. This varies by country and often by product category, so use the rate that applies to your transaction. |
| The amount above is | Whether the amount you entered already includes tax or not. |
When to use it
Invoicing a client
Enter your net fee, select “before tax”, and the calculator gives the tax to charge and the total to invoice.
Claiming tax back from a receipt
Receipts usually show the tax-inclusive total. Select “tax inclusive” and the calculator recovers the net amount and the tax component: the figure you claim.
Quoting a price to a consumer
Consumers generally expect an inclusive price. Work forward from your net price to the display price so the number on the shelf is the number at the register.
Comparing prices across regions
Tax rates differ by country and sometimes by state. Strip the tax out of both prices to compare the underlying cost of the item itself.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Adding tax to a $100 net price
A $100 net price with tax added, across a range of rates used around the world.
| Tax rate | Tax | Price before tax | Price including tax |
|---|---|---|---|
| 5% | $5.00 | $100.00 | $105.00 |
| 7.5% | $7.50 | $100.00 | $107.50 |
| 10% | $10.00 | $100.00 | $110.00 |
| 15% | $15.00 | $100.00 | $115.00 |
| 20% | $20.00 | $100.00 | $120.00 |
| 25% | $25.00 | $100.00 | $125.00 |
Removing tax from a $110 inclusive price
Working backwards from a tax-inclusive total to the net price.
| Tax rate | Tax | Price before tax | Price including tax |
|---|---|---|---|
| 5% | $5.24 | $104.76 | $110.00 |
| 10% | $10.00 | $100.00 | $110.00 |
| 15% | $14.35 | $95.65 | $110.00 |
| 20% | $18.33 | $91.67 | $110.00 |
| 25% | $22.00 | $88.00 | $110.00 |
Questions
How do I remove 10% GST from a price?
Divide the tax-inclusive price by 1.1. Equivalently, the GST component is the inclusive price divided by 11. Subtracting 10% gives the wrong answer.
What is the difference between GST, VAT and sales tax?
Mechanically they are similar consumption taxes charged as a percentage of price. VAT and GST are collected at each stage of the supply chain with credits for tax already paid; US-style sales tax is charged only at the final sale. For a single transaction the arithmetic here applies to all three.
Which rate applies to my sale?
It depends on the jurisdiction and often the category: food, medicine and books are frequently taxed differently or exempt. Check the rate that applies to your specific goods and location.
Should I display prices with or without tax?
Consumer-facing prices are usually required to be tax-inclusive in GST and VAT countries. Business-to-business quoting is more often net of tax. Local rules govern this, so check what applies to you.
To apply a discount before or after tax, use the discount calculator. For pricing and profitability, see margin and markup.