Discount Calculator
Free discount calculator for original price, discount percentage or fixed discount amount, sale price, total savings, and optional sales tax applied after the discount. Switch between Discount % and Discount Amount modes, use Swap to convert between percent and amount for the same deal, and see final payable when tax is enabled. Runs in your browser for quick retail, e-commerce, and invoice checks — planning math only, not tax or pricing advice.
How to Use the Discount Calculator
Enter the original price, choose Discount % or Discount Amount, optionally add tax applied after the discount, then press Calculate to see sale price, savings, tax, and final payable.
- Enter Original Price (pre-discount list or sticker price).
- Choose Discount % or Discount Amount mode.
- Enter the discount value in the selected mode.
- Optionally enter Tax % (applied to the sale price after discount).
- Press Calculate and review discount amount, sale price, total savings, tax, and final payable.
- Use Swap to switch between percent and amount, or Reset to clear.
Formulas
- Discount amount (percent mode) = original × discount % ÷ 100
- Sale price = original − discount amount
- Tax amount = sale price × tax % ÷ 100 (when tax is enabled)
- Final payable = sale price + tax amount
- Total savings = original − sale price
Worked examples
- Original 100, 20% off, no tax → discount 20, sale 80, savings 20, final 80.
- Original 250, 50 off, 10% tax → sale 200, tax 20, final payable 220.
- Original 80, 25% off → sale 60, savings 20 (25% of 80).
Common mistakes
- Applying tax to the original price instead of the discounted sale price (this tool uses tax after discount).
- Entering discount amount greater than original price.
- Confusing discount % with markup % on cost.
- Assuming multi-coupon stacking when only one discount is entered.
Limitations
Single primary discount in the UI. No currency conversion, shipping, or line-item baskets. Tax rules vary by country and product type — estimates only, not tax advice.
Privacy
Price and discount inputs stay in your browser. Values are not uploaded to ToolsLibrary servers.
FAQ
Can I enter discount as an amount instead of %?
Yes. Switch to Discount Amount mode to enter a fixed currency amount off the original price. The tool derives the equivalent discount percentage automatically.
How does optional tax work?
When you enter a Tax %, it is applied to the sale price after the discount (tax after discount). Final Payable = sale price + tax amount. Leave tax empty to skip tax.
What is the discount formula?
In percent mode: discount amount = original price × (discount % ÷ 100), sale price = original − discount. In amount mode: sale price = original − discount amount, and discount % = (discount amount ÷ original) × 100 when original > 0.
What does Swap do?
Swap toggles between Discount % and Discount Amount while keeping the same deal. In percent mode it fills the amount field from the percentage; in amount mode it fills the percentage from the amount and original price.
Can discount exceed 100%?
No. Discount percentage cannot exceed 100%, and discount amount cannot exceed the original price. The calculator returns a friendly error if values are out of range.
Does this support stacked or coupon-on-coupon discounts?
The UI applies one primary discount per calculation. The engine architecture supports stacked discounts for future use, but this page does not expose multiple sequential coupons yet.
Is tax calculated before or after discount?
After discount. Tax is computed on the discounted sale price, not on the pre-discount original price. Some jurisdictions use different rules — verify locally for filing or receipts.
Are my prices uploaded?
No. Original price, discount, and tax values are calculated in your browser and are not uploaded to ToolsLibrary servers.
Is this financial or tax advice?
No. Results are quick planning math for sale prices and savings. Confirm tax treatment and final invoices with your accountant or point-of-sale system.