Sales Tax Calculator
Add sales tax to a price or remove it from a tax-included total using your own rate.
Sales tax details
Choose Add tax for a price before tax, or Remove tax when the amount already includes tax.
Currency
Use this when your price is before sales tax is added.
Enter the combined state and local rate from your receipt, invoice, or official tax source.
Example rates
Examples only. These are not current or official rates. Always enter your own rate.
Total price including tax
£108.25
Final amount after adding sales tax.
Pre-tax price
£100.00
Price entered before tax.
Sales tax amount
£8.25
Tax portion at 8.25%.
Sales tax rate
8.25%
Rate you entered for this calculation.
Pre-tax / tax / total breakdown
Pre-tax price
£100.00
Sales tax
£8.25
Total
£108.25
This calculator is for estimates only. Sales tax rates vary by state, city, county, product type, and date. Check the official rate or your receipt for tax decisions.
Insights
What your sales tax result means
Calculation summary
Adding 8.25% sales tax to £100.00 gives a total of £108.25.
Tax portion
The sales tax in this calculation is £8.25 at a rate of 8.25%.
Removing tax correctly
The tax inside a tax-included total is not found by simply subtracting 8.25% from the total. Divide by one plus the rate instead.
Use your combined rate
The rate on a receipt often combines state, county, and city portions, so enter that full combined rate for the closest match.
Basics
What sales tax is
A tax on purchases
Sales tax is a consumption tax added to the price of many taxable goods and some services at checkout.
Added at the register
In many places the listed price is before tax, and the tax is added to the total the customer pays.
Collected by sellers
Businesses usually collect sales tax from customers and pass it on to the relevant tax authority.
Rules vary widely
Rates, taxable categories, and exemptions differ by location and can change over time.
Compare
Adding tax vs removing tax
Adding sales tax
Start from a price before tax. The tax amount equals the price times the rate, and the total equals the price plus the tax.
Removing sales tax
Start from a tax-included total. Divide by one plus the rate to find the pre-tax price, then subtract to find the tax.
Examples
Worked sales tax examples
These examples use a fixed rate to show the arithmetic. Replace the rate with your own to match your receipt.
| Scenario | Pre-tax price | Rate | Tax | Total |
|---|---|---|---|---|
| Add tax to a price | £100.00 | 8.25% | £8.25 | £108.25 |
| Remove tax from a total | £100.00 | 8.25% | £8.25 | £108.25 |
| Zero rate | £100.00 | 0% | £0.00 | £100.00 |
In the remove example, a £108.25 total that includes 8.25% tax breaks down into a £100.00 pre-tax price and £8.25 of tax.
Formula
Sales tax formula explanation
Add tax
Tax = Price × Rate ÷ 100The tax amount is the pre-tax price multiplied by the rate. The total is the price plus the tax.
Remove tax
Pre-tax = Total ÷ (1 + Rate ÷ 100)Used when the amount already includes tax. The result is the price before tax.
Tax amount
Tax = Total − Pre-taxThe tax portion is the difference between the total and the pre-tax price.
Use cases
Common ways to use this calculator
Sales tax rates are not universal. Choose the relevant combined rate for your location and the item you are buying.
Shopping
Estimate the final checkout total before you reach the register.
Budgeting
Plan a purchase by adding tax to the listed price.
Receipts
Work backward from a tax-included total to see the tax portion.
Invoices
Show a pre-tax price, tax amount, and total separately.
Quotes
Clarify whether a quoted price includes or excludes tax.
Bookkeeping
Separate the taxable amount and the tax for your records.
Tax notes
Rates, products, and accuracy
This calculator handles the arithmetic. The real rate depends on rules that vary by place and item.
Combined local rates
State, county, city, and special district taxes can stack, so the rate on a receipt may be higher than the state rate.
Product categories
Some items such as groceries or clothing may be exempt or taxed at a reduced rate depending on the jurisdiction.
Check official sources
Rates change over time. Confirm the current rate from your receipt or an official tax source before making decisions.
FAQ
Sales tax calculator questions
Multiply the pre-tax price by the sales tax rate you enter, then add that tax amount back to the price. For example, a price of 100 at a rate of 8.25% has a tax amount of 8.25 and a total of 108.25. This calculator uses the rate you type in, not a stored or official rate.
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Estimate only. This calculator is for general planning and education, not financial, tax, investment, legal, lender, or professional advice. Actual results can vary based on rates, fees, taxes, market conditions, lender rules, employer rules, contribution limits, and local regulations. Verify important decisions with a qualified professional, lender, official source, or relevant institution.
Related reading
Learn the formula, assumptions, examples, or context behind this tool.