Currency: USD
Enter all amounts in USD. Changing currency keeps numbers unchanged; no exchange rate is applied.
- Total including tax
- $106.00
- Tax amount
- $6.00
- Net amount
- $100.00
How it works
Apply the rate to taxable items only
If a verified receipt has 80 taxable and 20 exempt at an entered 10% rate, calculate tax on 80: tax is 8 and the combined total is 108. Applying the rate to 100 would overstate tax.
Working with tax-inclusive and pre-tax prices
At an entered rate of 8%, a pre-tax price of 100 becomes 108. If 108 already includes tax, divide by 1.08 to recover the pre-tax price of 100; the tax is 8. Multiplying 108 by 8% would incorrectly calculate tax on the tax-inclusive total. Choose the inclusive or exclusive mode to match your receipt. You supply the rate: the calculator does not look up an address, determine taxability, or apply exemptions.
Sales tax: formula and assumptions
Tax-exclusive total = net×(1+rate). Tax-inclusive net = gross/(1+rate).
The rate is your input. This calculator does not determine local tax applicability.
Tax from a selected known pair: formula and assumptions
Gross = net + tax = net × (1+rate).
Solve from the selected pair. Tax and rate cannot determine the net price when the rate is zero.
Worked example
Reference example currency: USD. These fixed examples do not change with your calculator preferences.
Using the Sales tax example:
- Amount ($)
- 100
- Tax rate (%)
- 6
- Amount includes tax?
- No — add tax
Tax-exclusive total = net×(1+rate). Tax-inclusive net = gross/(1+rate).
Example result
Total including tax: $106.00
Tax amount: $6.00
Net amount: $100.00
These are illustrative inputs. Change the values to explore a different scenario.
Formula references
- Investor.gov: financial tools (opens in a new tab)
- OpenStax: discounts, markups and sales tax (opens in a new tab)
References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.
Common questions
How do I remove tax already included in a total?
Divide the total by one plus the tax rate. The known-pair mode also solves from net and gross prices or from tax amount and a positive rate.
Does the calculator find the sales-tax rate for my address?
No. You supply the rate and determine whether the transaction is taxable or exempt.
Prepared by Finflo. See our methodology and editorial policy. Read the relevant professional-advice limitations.