Everyday math
Sales tax from entered rate
Add a supplied combined sales-tax rate to a pre-tax amount or separate tax from an inclusive total.
Your inputs
Complete the fields for your selected method. Zero means intentionally zero, not unknown. Currency selection labels amounts; it does not convert exchange rates.
How this calculation works
exclusive tax = taxable base × rate; inclusive tax = taxable inclusive amount × rate / (1 + rate)
No location, rate, nexus, registration, filing or product-taxability lookup. Supply the combined applicable rate and a known non-taxable portion. Only one rate is applied to one aggregate amount; item-level rounding and multiple tax classes can differ. Inclusive non-taxable portion is already tax-free. Not a tax-return estimator.
What information do I need?
Use records for the same job, equipment or accounting period. Only the fields for your selected entry method are required. An unknown amount is not zero.
Input definitions and where to find them
- Amount entry: Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
- Amount on selected basis (selected currency): Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
- Non-taxable portion included in that amount (selected currency): Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
- Combined sales-tax rate you provide (%): Use matching records or a clearly stated assumption for the indicated period. Prefilled figures are illustrative. An unknown value is not zero.
Use the Where to find this value controls beside the inputs for available work-it-out helpers. Estimates remain your assumptions; a helper does not verify the source figures.
Worked example
Example amounts use US dollars (USD).
Example answer: Total including supplied tax is $108.00 for the illustrative inputs below.
Example inputs
- Amount entry: Amount before tax
- Amount on selected basis: $100.00
- Non-taxable portion included in that amount: $0.00
- Combined sales-tax rate you provide: 8.00 %
- Total including supplied tax
- $108.00
- Tax amount
- $8.00
- Total before tax
- $100.00
- Taxable amount before tax
- $100.00
- Non-taxable portion supplied
- $0.00
These illustrative values are not recommended rates or industry averages. Replace every example input with your own figures.
Use the result well
Add a supplied combined sales-tax rate to a pre-tax amount or separate tax from an inclusive total.
Keep inputs on the same scope and time basis. Calculations retain precision internally; displayed values generally round to two decimal places, with extra precision for very small values and whole-unit rounding where required. Economic comparisons describe your supplied assumptions and do not guarantee future results.
This tool provides business arithmetic. It does not approve engineering designs, establish legal or tax treatment, select equipment or certify safe operating conditions.