Discount Calculator
Work out what a sale price really costs. Enter the initial price and either a percent-off value or a fixed discount amount, optionally add sales tax, and get the final price, the discount amount, and the effective discount rate — computed right in your browser.
Enter the initial price
Pick a currency symbol ($, €, £, ¥, ₹) and type the original pre-discount price of the item or order.
Choose how the discount is given
Select Percent off and enter the rate — 25 means 25% off — or select Fixed amount and enter the exact amount taken off, such as $20. The other field is disabled automatically.
Add tax if needed, then Calculate
Optionally tick "Add sales tax", enter the tax rate, and press Calculate. Read the final price (tax applied to the discounted price), the discount amount, and the effective discount rate. Copy the results or Reset to start over.
How the math works
- What formulas does this calculator use?
- Discount amount = discount percent × initial price. Final price = initial price − discount amount, which is the same as (100% − discount percent) × initial price. In Fixed-amount mode the discount amount is what you typed and the rate is derived from it.
- How is the sales tax applied?
- When "Add sales tax" is on, the tax rate is applied to the discounted price, not the original price: final price = (initial price − discount) × (1 + tax%). With the box unchecked, any value left in the tax field is ignored.
- What is the effective discount rate?
- In Percent-off mode it is the rate you entered. In Fixed-amount mode it is discount amount ÷ initial price × 100 — useful for comparing a "$30 off" coupon against a straight percentage sale.
- What values are rejected?
- The initial price must be greater than zero; the percent-off rate must be between 0 and 100; a fixed discount cannot exceed the initial price; negatives are rejected everywhere. Invalid fields show an inline error and no result is produced.
- Worked example
- Initial price $100, discount 10%: discount amount = 10% × $100 = $10, so final price = $100 − $10 = $90. With 8% sales tax added after the discount: $90 × 1.08 = $97.20 final.
Privacy: every calculation runs in your browser tab — no value you type is sent anywhere. Copy results uses your clipboard only. Currency symbols are display labels only; this tool does no currency conversion.