Quick Answer & Formula
Excel
Sheets
Beginner
Add %: =Price * (1 + Tax_Rate) | Subtract %: =Price * (1 - Discount_Rate) To add a percentage (e.g. 8.25% sales tax): =Price * (1 + 0.0825). To subtract a percentage (e.g. 20% discount): =Price * (1 - 0.20).
How to Add or Subtract a Percentage in Excel (Sales Tax & Discounts)
Whether applying state sales taxes, calculating price markups, or computing promotional Black Friday discounts, here are the standard retail formulas.
1. Adding a Percentage (e.g. Sales Tax)
$$\text{Final Total} = \text{Base Price} \times (1 + \text{Percentage})$$
= Price * (1 + Tax_Rate)Invoicing Table Example:
| Item | Base Price (A) | Sales Tax Rate (B) | Tax Amount Formula | Tax Amount ($) | Total with Tax Formula | Final Price |
|---|---|---|---|---|---|---|
| Laptop Pro | $1,200.00 | 8.25% | =A2 * B2 | $99.00 | =A2 * (1 + B2) | $1,299.00 |
| Wireless Earbuds | $150.00 | 7.50% | =A3 * B3 | $11.25 | =A3 * (1 + B3) | $161.25 |
2. Subtracting a Percentage (e.g. Discount)
$$\text{Discounted Price} = \text{Original Price} \times (1 - \text{Discount Rate})$$
= Price * (1 - Discount_Rate)- Example:
$80.00item with a25%discount:
Returns:=80 * (1 - 0.25)$60.00(Discount savings =$20.00).
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Frequently Asked Questions
How do I extract the original pre-tax price from a tax-inclusive total?
Divide the total by (1 + Tax_Rate): =Total_Price / (1 + Tax_Rate). For example, $108.25 at 8.25% tax: =108.25 / 1.0825 = $100.00.