# Free sales tax calculator

> Enter a price and your local tax rate to find the tax amount and total cost. The optional discount field applies the markdown before tax, just like stores do.

Add sales tax to any price and see the final total. Supports optional pre-tax discounts.

**Interactive version:** https://onlinecalculator.me/finance/sales-tax/
**Category:** Finance

## How to use

1. Enter the pre-tax **price** of the item or service.
2. Enter your local **tax rate** (combined state + county + city).
3. Optionally enter a **discount %** if the item is on sale.
4. The tax amount, final total, and effective rate appear instantly.

## Formula

- **Tax = price × (rate ÷ 100)**
- **Total = price + tax**

When a discount is applied, the markdown comes off first, then tax is applied to the smaller amount:

1. Discounted price = price × (1 − discount% ÷ 100)
2. Tax = discounted price × (rate ÷ 100)
3. Total = discounted price + tax

## Worked examples

### $100 item at 8% tax, 20% off

- After discount: 100 × 0.80 = $80
- Tax: 80 × 0.08 = $6.40
- Total: 80 + 6.40 = **$86.40**

### Reverse — finding price from a $108 receipt at 8% tax

- Pre-tax = 108 ÷ 1.08 = **$100**
- Tax paid = 108 − 100 = **$8**

## Notes

- **Combined rates** — most states have state + county + city layers. Look up your address on your state revenue website and enter the combined rate as one number.
- **Discount before tax** is the standard U.S. retail convention, and what this calculator follows. A small number of states (and most of Europe's VAT) apply tax to the sticker price — those rules aren't captured here.
- **Exemptions** — several states exempt groceries, clothing, or prescription drugs. This calculator treats every dollar as taxable; strip the exempt portion from the price before you enter it.

## Frequently asked questions

### How is sales tax calculated?

Tax = price × (rate ÷ 100). The total is price + tax. If a discount applies, the discount reduces the price first, then tax is applied to the discounted amount.

### What is the effective tax rate?

When a discount is applied, the effective tax rate is the tax as a percentage of the original undiscounted price — always less than the nominal rate.

### Does this include local and state tax?

The calculator takes whatever combined rate you enter. Look up your state + city + county combined rate on your state's revenue website and enter it as one number.

### How do I reverse-calculate price from total?

Pre-tax price = total ÷ (1 + rate/100). For example, if the total is $108 at 8% tax: 108 ÷ 1.08 = $100.

### How do I share my calculation?

Click "Share with my numbers" to copy a URL that restores your price and rate.

## Sources

- [State and Local Sales Tax Rates, 2026](https://taxfoundation.org/data/all/state/sales-tax-rates/) — Tax Foundation
- [Sales Tax](https://en.wikipedia.org/wiki/Sales_tax) — Wikipedia

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