Discount Calculator Guide: Sale Price, % Off & Reverse Math
A complete overview of the Discount / Sale Price Calculator — finding a sale price, checking the real percent off, reversing to the original price, and stacking discounts.
Discount math has three directions and a stacking trap most people don't expect — this calculator covers all of it from one tool.
What it calculates
- Find sale price: original price + one or more stacked discounts (percent or dollar amount, applied in sequence) → sale price, amount saved, and the real effective discount percent.
- Find discount %: original price + sale price → the actual percent off, useful for checking an advertised discount.
- Find original price: sale price + discount % → what the item cost before the markdown.
- Optional sales tax: applied to the final discounted price, matching how registers actually calculate tax at checkout.
Why stacked discounts get their own breakdown table
Showing each discount step separately — price before, amount off, price after — makes the compounding effect visible instead of hidden inside a single final number. When the discounts stacked don't add up to their naive sum, the calculator flags the gap directly.
Once you know the sale price, our Sales Tax Calculator handles the tax math on its own if you need to work with just the tax side separately.