Sales Tax Calculator
Add tax to a price—or separate tax from a total that already includes it.
Verify this calculatorMaintained
See what the result uses—and what it cannot know.
Sumvoro calculates deterministically from the visible inputs. It does not invent lender terms, local rules, market values, medical facts, or professional judgments.
- 1 · InputsCheck every entered value against the latest statement, quote, measurement, or official source.
- 2 · Formula
Add tax: total = price × (1 + rate ÷ 100). Included tax: pre-tax price = total ÷ (1 + rate ÷ 100). - 3 · SensitivityUse Insights to run a lower and higher case. If the conclusion changes easily, collect better information or leave more margin.
- 4 · ScopeThis tool is maintained and covered by automated calculation tests. Provider timing, rounding, and omitted facts can still change a real-world result.
- Formula release
- 2026.10-r4
- Release date
- October 10, 2026
- Review status
- Maintained
- Source review
- September 12, 2026
Optional readingLearn how this calculator works
How the sales tax calculator works
Add sales tax to a price or calculate the tax portion already included in a total using a rate you enter.
Add tax: total = price × (1 + rate ÷ 100). Included tax: pre-tax price = total ÷ (1 + rate ÷ 100).
Read our calculation methodology and limitations.
Example
At a 7% rate, a $100 price becomes $107. Removing the included tax from $107 gives a $100 pre-tax price and $7 tax.
What affects the result
- Use the combined applicable rate for the transaction.
- This tool does not determine whether an item is taxable.
- Totals are rounded to cents; item-by-item rounding can differ.
Frequently asked questions
Does Sumvoro find the rate for my address?
No. Enter the applicable rate yourself and confirm local rules and exemptions.
Why not subtract 7% from a tax-inclusive total?
The rate applies to the pre-tax price, not the total. Divide a tax-inclusive amount by 1.07 to remove a 7% tax.