Discount Calculator
Find the real sale price in seconds — including stacked discounts stores hope you won't calculate.
Find the real price
100 * 1.2.Type a number or a formula, like 35 or 70 / 2.
How to Use the Discount Calculator
Enter the original price, pick the discount percentage (or type your own with "Custom discount..."), and add a second discount if the store stacks one — like "30% off plus an extra 10% at checkout." The calculator shows the final price, exactly how much you save, and the true combined discount.
Watch the stacked-discount math especially: two discounts never simply add up, and stores count on shoppers not noticing.
The Discount Formula
One discount is straightforward:
Sale Price = Original Price × (1 − Discount%)
So 30% off $120: $120 × (1 − 0.30) = $120 × 0.70 = $84.00. You save $36.
The shortcut worth memorizing: convert "X% off" into a multiplier. 25% off → multiply by 0.75. 40% off → multiply by 0.60. One multiplication and you have the price — faster than any calculator once it clicks.
Worked Example: 30% Off $120
Step 1 — Discount amount
$120 × 30% = $120 × 0.30 = $36.00 saved.
Step 2 — Sale price
$120 − $36 = $84.00. (Or directly: $120 × 0.70 = $84.00.)
Step 3 — Add a stacked 10%
The extra 10% comes off $84, not $120: $84 × 0.10 = $8.40. Final price: $75.60. Total saved: $44.40 — an effective 37% off, not 40%.
Stacking Multiple Discounts
"Extra 20% off sale items!" sounds like 20% + 30% = 50% off. It isn't. Discounts apply sequentially — each one discounts the already-reduced price:
Final = Price × (1 − d1) × (1 − d2)
| Advertised | Real combined discount | $100 item costs |
|---|---|---|
| 20% + 20% | 36% | $64.00 |
| 30% + 10% | 37% | $63.00 |
| 50% + 20% | 60% | $40.00 |
| 25% + 25% + 10% | 49.4% | $50.63 |
The combined discount is always less than the sum. Retailers know this; now you do too. Use the calculator's extra-discount box to see the real number before you get excited.
Reverse Discount: Find the Original Price
Sometimes you only see the sale price and the discount — "Now $84, was 30% off!" What was the original price? Divide by what's left:
Original Price = Sale Price ÷ (1 − Discount%)
For $84 at 30% off: $84 ÷ 0.70 = $120.00. This is handy for checking whether a "was" price on the tag is honest — if the math doesn't reproduce the claimed original, the anchor was invented.
It also works for tax-backwards situations. See a "$91.80 out the door" price with 8% sales tax and want the pre-tax price? Same formula: $91.80 ÷ 1.08 = $85.00. Our Sales Tax Calculator does this in reverse mode automatically.
Discount vs Coupon vs Cashback: Which Wins?
Not all savings are equal. Ranked by real value on a $100 purchase:
- Straight discount (best). 20% off = $80 out the door. Simple, instant, no strings.
- Cashback / rewards. 5% back on your card = $95 net, but only if you pay the card off — one month of interest at 24% APR wipes out years of cashback.
- Store credit / "bonus cash." "$20 in bonus cash on $100!" sounds like 20% off, but it forces a second purchase, often with exclusions and expiry dates. Value it at half its face amount unless you were buying anyway.
- Rebates (worst). Mail-in rebates count on you forgetting. Redemption rates are famously low — treat an unredeemed rebate as $0 and be pleasantly surprised.
When comparing, always reduce everything to final out-of-pocket dollars. That's the only number that matters, and it's exactly what the calculator above computes.
How Stores Use Sale Psychology
- Anchoring. "$200, now $120!" makes $120 feel like a steal — even if the item never actually sold at $200. The "original" price is often inflated or rarely charged.
- The 9-ending. $84.00 becomes $83.99. Your brain reads "eighty-something" and files it as cheaper than $84, though the difference is a penny.
- Percentage vs dollars. "50% off!" sounds bigger than "Save $10" on a $20 item — but they're identical. On expensive items, flip it: "Save $300" hits harder than "15% off," which is why stores show whichever looks bigger.
- Fake urgency. "Sale ends Sunday!" resets every Monday. If the discount is always available, it's the real price — compare it against competitors, not against the crossed-out number.
The defense is simple: decide what the item is worth to you before looking at the discount, then use this calculator to check the real final price. A 40% discount on something overpriced is still overpaying.
My saved numbers reuse them in any calculator
Save a number once — like your rent or hourly rate — then just type its name instead of the number, in any calculator here. You can also type formulas like 5000 * 1.1 right into any box.
Saved only in this browser — nothing is sent to us.
Frequently Asked Questions
How do you calculate a discount?
Multiply the original price by one minus the discount as a decimal. For 30% off $120: $120 × (1 − 0.30) = $120 × 0.70 = $84. You save $36.
What is 25% off $80?
25% off $80 is $60. Calculation: $80 × 0.75 = $60, so you save $20.
How do I calculate percent off?
Subtract the sale price from the original price, divide by the original price, and multiply by 100. A $120 item selling for $84 is ($120 − $84) ÷ $120 × 100 = 30% off.
Do discounts stack on top of each other?
They apply sequentially, not additively. An extra 10% off a 30%-off $120 item comes off the $84 sale price ($8.40), giving $75.60 — a true 37% off, not 40%. Two 20% discounts equal 36% off, not 40%.
How do I find the original price from a sale price?
Divide the sale price by one minus the discount as a decimal. A $84 item at 30% off was originally $84 ÷ 0.70 = $120.