# Sales Tax Calculator

- **URL:** https://codeasystem.com/calculators/finance/sales-tax-calculator/
- **Category:** finance
- **Description:** Add sales tax to a pre-tax price or extract the tax already inside a tax-inclusive total.
- **Primary output:** Total with tax: $87.09

## Inputs
- Amount (name: `amount`, type: number, prefix: $, example: 79.99)
- Tax rate (name: `tax`, type: number, example: 8.875)
- Direction (name: `mode`, type: select)

## Outputs
- Total with tax: $87.09
- Tax amount: $7.10
- Pre-tax amount: $79.99

## Formula / methodology
```
With tax: Total = Price × (1 + t)     Extract: Price = Total / (1 + t)
```

Adding multiplies the price by one-plus-the-rate. Extraction divides the tax-inclusive total by the same factor; necessary in VAT/GST countries and for US receipt reconciliation where tax must be backed out of a final number.

## Assumptions & limitations
- Single flat tax rate; no layered local/state/district rates unless combined by hand.
- Extraction assumes tax was included in the entered total.
- Rates vary by jurisdiction; confirm yours with your state or national authority.

## Example
Adding 8.875% tax to $79.99 gives $87.09 total. Working backwards, an $87.09 receipt at the same rate contains $7.10 of tax hiding inside it.

Result for these inputs:

```
Total with tax: $87.09
```

## About this calculator
### Sales tax versus VAT

US sales tax is added at the register, so shelf prices exclude it. VAT/GST systems embed tax in displayed prices, which is why the extract direction matters abroad; the sticker price already contains tax.

### Combined jurisdiction rates

Many US locations stack state + county + city + special district rates. Sum them before entering; the calculator handles any single resulting rate.

## FAQs
### How do I find my local rate?

US: your state Department of Revenue publishes combined rate lookup tables. Elsewhere, the national VAT/GST rate applies to most goods.

### Why extract tax at all?

Businesses reclaim or remit only the tax portion of receipts, and budget travelers often want the pre-tax comparison across countries.

### Does it handle exempt items?

Enter 0% for exempt purchases; groceries, medicine and clothing exemptions vary widely by jurisdiction.

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Last updated: 2026-08-23 · Version: 1.0.0 · [HTML version](https://codeasystem.com/calculators/finance/sales-tax-calculator/)