glunty Sales Tax Calculator (Add or Remove Tax)
Pre-tax price and rate to tax and total. Or reverse a tax-inclusive total.
- Runs in your browser
- No sign-up
- No watermark
- No installs
Add sales tax
Breakdown
Reverse: remove tax from a total
Have a tax-inclusive total? Back out the pre-tax price and the tax.
Breakdown
What this tool does
Works out sales tax two ways. In add mode, enter a pre-tax price and a tax rate and it shows the tax amount and the final total live as you type. In reverse mode, enter a tax-inclusive total (the kind printed on a receipt) and the same rate, and it backs out the pre-tax price and the tax that was already baked in. The reverse math divides by 1 plus the rate, which is the correct way to un-tax a total. Everything runs in your browser; nothing is uploaded.
How to use it
For add mode, type a price and a rate; the tax and total update instantly. Example: 100 at 8.25% gives 8.25 in tax and a total of 108.25. For reverse mode, type the total you paid and the rate, and read off the pre-tax price. Example: a 108.25 total at 8.25% backs out to 100.00 before tax, with 8.25 of that being tax. Leave a rate at 0 and the tax is 0 and the total equals the price.
Common use cases
- Adding local sales tax to a sticker price before you check out.
- Backing the pre-tax subtotal out of a receipt that only shows the grand total.
- Splitting a VAT-inclusive or GST-inclusive price into net and tax for an expense report.
- Quoting a client a price plus tax, or working out the tax already inside a quoted total.
- Checking a cash register or invoice figure against the arithmetic.
Common pitfalls
- You cannot un-tax by subtracting the percent. Taking 8.25% off a 108.25 total gives 99.32, which is wrong, because the tax was charged on the smaller pre-tax price. Divide by 1.0825 instead to get the correct 100.00.
- Use the combined rate. The rate at the register is often a state rate plus county and city add-ons. Enter the actual combined rate from your receipt, not just the headline state figure.
- Tax comes after a discount. In most places sales tax is charged on the discounted price, not the original. Apply the markdown first, then add tax to the reduced amount.
Frequently asked questions
- How do I calculate sales tax on a price?
- Multiply the pre-tax price by the tax rate written as a decimal, then add that to the price. For example, a rate of 8.25 percent on a price of 100 is 100 times 0.0825, which is 8.25 in tax, for a total of 108.25. This tool does that arithmetic live as you type and shows both the tax amount and the final total.
- How do I remove sales tax from a total (reverse sales tax)?
- Divide the tax-inclusive total by 1 plus the rate as a decimal. The pre-tax price is total divided by (1 plus rate). For example, a total of 108.25 at 8.25 percent is 108.25 divided by 1.0825, which is 100.00 before tax, so the tax portion was 8.25. Use the reverse box in this tool to back out the pre-tax price from any receipt total.
- Why can I not just subtract the tax percent from the total to get the pre-tax price?
- Because the tax was charged on the smaller pre-tax price, not on the larger total. Subtracting the rate as a percent of the total removes too much. The correct method divides by 1 plus the rate. On a 108.25 total at 8.25 percent, subtracting 8.25 percent of the total gives 99.32, which is wrong; dividing by 1.0825 gives the correct 100.00.
- What sales tax rate should I use?
- Use the combined rate that applies at the point of sale, which is often a state rate plus county and city add-ons. US rates commonly land between 4 and 10 percent depending on location, and some items such as groceries or medicine are taxed at a lower rate or not at all. This tool does not know your local rate, so enter the one printed on your receipt or published by your tax authority.
- Does this work for VAT or GST?
- Yes. The add and reverse math is identical for any single-rate percentage tax, so you can use it for VAT or GST as well as US sales tax. The main difference is presentation: many countries quote VAT-inclusive prices, which is exactly what the reverse mode is for. For multiple or tiered rates, run each rate separately.
- Should sales tax be applied before or after a discount?
- In almost every jurisdiction, sales tax is charged on the discounted price, not the original sticker price. Apply any discount first, then add tax to the reduced amount. To combine a percent-off deal with tax in one place, the discount calculator handles both steps in order.
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