Financial

Sales Tax Calculator

Add or reverse sales tax with discounts and a clean before/after breakdown.

Inputs

Defaults are prefilled so the result is visible immediately.

Mode

Price or tax-included total

Sales tax rate%

Discount before tax

Results

Results update as the calculator inputs change.

Total after tax

$134.06

Sales tax

$9.06

Pretax price

$125.00

Tax-included total

$134.06

Tax share of total

6.76%

Formula and Assumptions

Forward mode: total = discounted price x (1 + tax rate). Reverse mode: pretax = total / (1 + tax rate).

Discount is applied before tax in add-tax mode.

Reverse mode extracts the tax portion from a tax-included total.

Reference Upgrade

Built from the Calculator.net model, with added context.

Live validation and instant result updates instead of a submit-only workflow.

Multiple decision metrics are shown together, not only the primary answer.

Formula notes and assumptions are visible on the page so the math is easier to audit.

Reference Model

Modeled after the input style and primary output on Calculator.net's Sales Tax Calculator.

The page keeps the math in one place and exposes the assumptions beside the result.

Default inputs: mode=add, price=125, taxRate=7.25, discount=0