Discount calculator
It is Black Friday and the $129.99 headphones you have been watching finally drop 25%. At checkout, an extra 10% promo code stacks on top.
- Formula explained step by step
- Worked examples with real figures
- 100% local math — nothing is uploaded
Discount calculator
Enter your numbers and press Calculate
Worked discount examples, step by step
How much do you actually save on a deal? Four everyday US shopping scenarios, fully worked out:
- $129.99 headphones at 25% off for Black Friday: 129.99 × (1 − 0.25) = $97.49. You save $32.50.
- $499.99 TV at 20% off plus a 10% promo code: 499.99 × 0.80 = $399.99; then 399.99 × 0.90 = $359.99. Total saved: $140.00 — an effective 28%, not 30%.
- $64 sneakers with a 40% clearance tag and an extra 15% app coupon: 64 × 0.60 = $38.40; then 38.40 × 0.85 = $32.64. Effective discount: 49%.
- $1,200 laptop with a 5% student discount: 1,200 × 0.95 = $1,140. A small percentage on a big ticket still saves $60.
Notice the pattern in the stacked cases: the combined discount is always smaller than the simple sum, because the second percentage only bites into what is left after the first one. That is why 40% plus 15% lands at 49% rather than 55% — and why retailers love advertising 'extra percent off' on clearance.
How to use the discount calculator
The calculator has three fields, all of which accept decimals:
1. Original price: the sticker price before any markdown, for example $129.99. 2. Discount: the main percentage off, the −25% on the shelf tag. 3. Extra discount (optional): use it when a coupon, promo code, or loyalty offer stacks on top of the already reduced price. Leave it at 0 if there is no second deal.
You instantly get three results: the final price you will pay, the total amount saved, and the effective discount — the true combined percentage of both markdowns.
Three practical ways to use it:
- During Black Friday or end-of-season clearance, check whether an 'extra 15% off clearance' beats a flat 40% deal elsewhere (a 30% tag plus 15% coupon is only 40.5% effective).
- Audit your cart: if a store applies the coupon before the markdown, the final price should be identical — multiplication is commutative — so any mismatch means something else changed.
- Budget before tax: the result is the pre-tax amount; add your state and local sales tax on top to estimate the register total.
Discount and stacked discount formula
Chained discounts are multiplicative, not additive. These are the three formulas behind the calculator:
final_price = original_price × (1 − d1/100) × (1 − d2/100)
total_saved = original_price − final_price
effective_discount = (total_saved / original_price) × 100
Worked example: a $200 jacket at 30% off with an additional 10% coupon.
1. 200 × (1 − 30/100) = 200 × 0.70 = $140 2. 140 × (1 − 10/100) = 140 × 0.90 = $126 3. Saved: 200 − 126 = $74 4. Effective discount: 74 / 200 × 100 = 37%
Note that 30 + 10 = 40, yet the effective rate is 37%: the second percentage only acts on the remaining $140, not on the original $200. With a single discount, set d2 to 0 and the expression collapses to price × (1 − d/100), the classic percentage formula. A handy shortcut for any number of stacked deals: multiply the 'remaining fractions' together (0.70 × 0.90 = 0.63 means you pay 63%, so you save 37%).
This tool is for educational and price-comparison purposes and does not constitute financial advice.
About this calculator
Quick math says 35% off, but the register disagrees: stacked discounts multiply instead of adding, so the real saving is 32.5%. This discount calculator does the math instantly. Enter the original price, the main discount, and an optional second discount or coupon, and you get the final price, the total amount saved, and the effective discount percentage — the number that actually matters when you compare deals across stores or decide whether a coupon is worth hunting for. Keep in mind the result is sticker-price math; in most US states, sales tax is added afterwards at the register.
Frequently asked questions
Why doesn't a 25% discount plus an extra 10% equal 35% off?
Because the second discount applies to the already reduced price, not the original. On $100: 25% brings it to $75, and 10% off $75 only removes another $7.50. You pay $67.50 — an effective 32.5%. The more discounts you chain together, the bigger the gap versus simple addition.
How do I estimate a discount in my head, without a calculator?
Use the 10% trick: move the decimal point one place to the left. On $60, 10% is $6. For 25%, add 10% twice plus half of 10% (6 + 6 + 3 = $15). For 5%, take half of 10%. Combining these building blocks covers nearly every percentage you will meet in a store while you are still in line.
Does the final price include sales tax?
No. In the US, sticker prices exclude sales tax: the discount applies to the pre-tax price, and your state and local sales tax is then added on the discounted amount at the register. The calculator gives you the discounted pre-tax figure. Shopping from EU or UK stores is the opposite — displayed prices already include VAT, so the result matches what you pay.
How do I find the original price from the discounted price?
Divide the discounted price by (1 − discount/100). Example: you paid $54 at an effective 32.5% off, so 54 / 0.675 = $80. It is the inverse of the discount formula and comes in handy for checking whether the 'was' price a retailer shows was genuine or quietly inflated right before the sale.