40% off. Of a price they raised last week. Let's see what you actually save.
Use this free discount calculator to find your savings and the final sale price for any percentage off. Enter the original price and the discount percent and get both numbers — for sales, coupon codes, clearance racks, and negotiating with yourself in a store aisle.
Discount math is easy in isolation and deliberately confusing in the wild: stacked coupons, "extra 20% off sale prices," and tags showing three numbers. This page covers the base case and the tricks underneath it.
What This Discount Calculator Does
- Calculates the amount saved and the final price after a discount
- Handles any percentage, from a 5% coupon to 70% clearance
- Explains stacked discounts so "50% + 20%" stops feeling like 70%
- Works backwards too: find the original price from a sale price (see notes)
How to Use the Discount Calculator
Inputs:
- Original Price — the pre-discount price
- % Off — the discount percentage (default 20)
Steps:
- Enter the original price
- Enter the discount percentage
- Click Calculate for savings and the new price
- Stacked discounts? Run it twice — apply the first discount, then run the result through the second
How the Calculation Works
Savings = Price × (Off ÷ 100)
New Price = Price − Savings = Price × (1 − Off ÷ 100)
- Stacked discounts multiply, they do not add: 50% then 20% = 0.5 × 0.8 = 0.40, so 60% off, not 70%
- Reverse it: Original = Sale Price ÷ (1 − Off ÷ 100). A $60 item at 25% off started at $80
- Mental shortcuts: 25% off = three-quarters of the price · 33% off ≈ two-thirds · 40% off = 60% of the price, so multiply by 0.6
- Sales tax applies to the discounted price, so a discount saves you a bit of tax too
Worked Example: $180 jacket, 30% off, then an extra 15% coupon
- First discount: savings = 180 × 0.30 = $54 → price = $126
- Coupon on the sale price: 126 × 0.15 = $18.90 → price = $107.10
- Total saved: 180 − 107.10 = $72.90, which is 40.5% off, not the 45% the signs imply
- Add 8% sales tax and you pay $115.67. The jacket is still nicer than the arithmetic.
Tips (From People Who Have Made These Mistakes)
- Check the price history on anything expensive. "Was $200" is a marketing claim, not a fact
- A discount on something you did not want is not savings, it is spending with a compliment attached
- "Buy one get one 50% off" is 25% off the pair. "Buy 2 get 1 free" is 33% off three
- Compare final prices, not discount percentages. 60% off a $200 item beats 40% off a $100 item only if you wanted the $200 item
Frequently Asked Questions
How do I calculate a discount?
Multiply the price by the percentage as a decimal for savings, then subtract. $80 at 25% off: 80 × 0.25 = $20 saved, $60 final. Or multiply directly by 0.75.
How do I calculate 20% off?
Take 10% (move the decimal one place left), double it, subtract. $45 → $4.50 → $9 off → $36. Or multiply by 0.8.
How do stacked discounts work?
They apply sequentially, so they multiply: 30% then 20% leaves 0.7 × 0.8 = 0.56 of the price, which is 44% off — not 50%. Retailers rely on this arithmetic gap.
How do I find the original price from a sale price?
Divide by (1 − discount). A $39 item marked 35% off was 39 ÷ 0.65 = $60. Useful for checking whether the "original price" on the tag is plausible.
Is sales tax calculated before or after the discount?
After. Tax applies to what you actually pay, so the discount reduces the tax too. Use the sales tax calculator on the discounted figure.
Mini Roast Disclaimer
We roast the number, not you. Saving $72 on a jacket you did not need is still spending $107, and the calculator has done the math both ways.
Reality Check
The arithmetic is exact; the "original price" often is not. Reference prices get inflated before sales, and stacked offers save less than they appear. Decide what an item is worth to you first, then check whether the discounted price clears that bar.