Everyday Math

Discount Calculator

See exactly what a sale price will be and how much you'll save. Supports an optional second (stacked) discount like "extra 20% off clearance."

How discounts are calculated

The formula is straightforward: sale price = original price × (1 − discount ÷ 100). A $60 jacket at 30% off costs 60 × 0.70 = $42, saving you $18.

Stacked discounts don't add up — they multiply

"30% off, plus an extra 20% off at checkout" is not 50% off. The second discount applies to the already-reduced price:

$60 → 30% off → $42 → extra 20% off → $33.60. That's an effective total discount of 44%, not 50%. Retailers rely on shoppers overestimating stacked deals — this calculator shows the true combined percentage.

Common discount shortcuts

DiscountMental shortcut$80 item becomes
10% offTake off one decimal place$72
25% offQuarter off — divide by 4, subtract$60
50% offHalf price$40
70% offYou pay 30% — multiply by 0.3$24

Tip: instead of computing what comes off, compute what you pay. "40% off" simply means "pay 60%," and multiplying by 0.6 is one step.

Watch out for these sale tricks

Frequently asked questions

How do I find the original price from a sale price?

Divide by what you paid as a fraction. If $42 was 30% off, the original was 42 ÷ 0.70 = $60.

Is tax applied before or after the discount?

In the US, sales tax is charged on the discounted price you actually pay (for store discounts). Manufacturer coupons can differ by state.

What's the difference between a discount and a markdown?

They compute the same way — "markdown" is the retailer-side term for a permanent price reduction, while a discount is often temporary or conditional.