Calcs4All

APR 23 · 2026

Sales tax calculator

Calculate sales tax and totals from a subtotal and tax rate.

What this calculator covers

Calculate sales tax on a subtotal and review the final total with a deterministic step-by-step explanation.

This launch calculator is built for clear, low-friction purchase checks rather than tax policy interpretation.

Frequently asked questions

How is sales tax calculated?
Sales tax is the subtotal multiplied by the tax rate expressed as a decimal. A $50 purchase at an 8% rate produces $4.00 in tax, for a $54.00 total. This calculator applies that formula and rounds to the nearest cent.
What tax rate should I enter?
Enter the combined rate that applies to your purchase — this is usually state rate plus any county or city rate added on top. Combined rates vary widely by location. Your state's department of revenue website typically has a lookup tool for the rate at a specific address.
Does this handle tax-exempt items?
No. The calculator applies the tax rate to the full subtotal. If some items in a purchase are tax-exempt (such as groceries or prescription drugs in certain states), exclude those items from the subtotal before entering it.
Why might my receipt total differ slightly?
Some retailers calculate sales tax on individual line items before summing, while others apply the rate to the order total. These different rounding approaches can produce a cent or two of difference compared with applying the rate to a single combined subtotal.

Tool

Run the calculation

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RESULT · SALES TAX

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Primary result

$108.25

Sales tax on $100.00 at 8.25% is $8.25, for a total of $108.25.

Tax amount
$8.25
Final total
$108.25

Step-by-step solution

  1. 1.Convert 8.25% to a decimal: 0.0825.
  2. 2.Multiply the subtotal $100.00 by the decimal tax rate.
  3. 3.Add the tax to the subtotal to get $108.25.

Walkthrough

Visual walkthrough

Sales tax is a flat-rate markup layered onto the untaxed subtotal.

  1. 01

    Convert the tax rate

    8.25% ÷ 100 = 0.0825

    A decimal tax rate is easier to multiply against the purchase subtotal.

  2. 02

    Calculate the tax amount

    $100.00 × 0.0825 = $8.25

    This isolates the tax charge before it is added back to the purchase.

  3. 03

    Add subtotal and tax

    The checkout total is the subtotal plus the calculated tax amount.

    Total due $108.25