Discount Calculator
Find the sale price and savings after a percentage discount.
The Discount Calculator answers the two questions that matter in front of a sale rack: what will this actually cost, and how much am I saving? Retail pricing is deliberately designed to make that arithmetic slightly awkward — odd prices, stacked promotions, and percentages that sound larger than they are. This page shows the exact formula, explains why sequential discounts never add up the way the signage implies, and covers how tax, coupons, and 'original price' claims change the number you finally pay.
How to use this calculator
- Enter the original price.
- Enter the discount percentage.
- The result shows the final price and the amount saved.
The formula
Final price = Price × (1 − Discount% ÷ 100)- Price
- Original (pre-discount) price
- Discount%
- The advertised percentage off
How it works
A 25% discount means you pay 75% of the original: 89.99 × 0.75 = 67.49.
Stacked discounts multiply rather than add: 20% off then 10% off is ×0.8 ×0.9 = ×0.72, a 28% total discount — not 30%.
Worked example
A $89.99 jacket is 25% off.
- 1Savings = 89.99 × 0.25 = 22.50
- 2Final = 89.99 − 22.50
You pay $67.49 and save $22.50.
The percentage-off formula
A percentage discount multiplies the price by one minus the rate. A 25% discount means you pay 75% of the original: 89.99 × 0.75 = $67.49, a saving of $22.50.
To reverse the calculation and find the original price from a sale price, divide instead of multiply: a $60 item after 25% off originally cost 60 ÷ 0.75 = $80. This is the fastest way to check whether an advertised 'was' price is plausible.
Why stacked discounts multiply
Applying 20% off and then a further 10% off does not give 30% off. The factors multiply: 0.8 × 0.9 = 0.72, so you pay 72% and the real discount is 28%. Order does not matter — the result is identical either way.
Fixed-amount coupons behave differently. A $10 coupon on a $50 item is 20% off, but on a $200 item it is only 5%. When choosing between a percentage and a fixed amount, compare them at the actual price rather than in the abstract.
Tax, shipping, and judging a real deal
Sales tax is normally charged on the discounted price, so a discount reduces the tax too. The figures here are pre-tax; add your local rate to the final price for the amount at the register.
A discount is only a saving if you were going to buy the item anyway. Compare the sale price against the typical selling price elsewhere rather than against the marked 'original' price, which is often an anchor rather than a price anyone paid.
Stacked discounts and coupon order
Successive percentage discounts multiply. Thirty percent off followed by twenty percent off leaves 0.70 x 0.80 = 56% of the price, a 44% total reduction rather than 50%.
Mixing a percentage discount with a fixed-amount coupon is different: order matters. Taking the fixed amount off first and then the percentage saves more than the reverse.
Retailers usually specify the order in their terms. If you can choose, apply fixed-value coupons before percentage discounts.
Tax, shipping, and the real total
Discounts almost always apply to the pre-tax price, so tax is calculated on the reduced amount. That makes the effective saving slightly larger than the headline percentage on the final bill.
Shipping is frequently excluded from discounts and can erase a modest saving entirely on small orders. Compare the delivered total, not the item price.
Free-shipping thresholds encourage adding an item to qualify. Adding something you did not want to save on postage is a loss, not a saving.
Judging whether a deal is genuine
Compare against the price you have actually seen recently, not the 'was' price on the tag. Reference prices are sometimes brief or seasonal.
Check price history where a tracker exists, and check the same item at two other retailers before committing to a large purchase.
Buy-one-get-one and multibuy offers only save money if you would have bought both units anyway; otherwise the unit price is the honest measure.
Working backwards and cross-checking
To recover the original price from a sale price, divide by one minus the discount: 63 at 30% off implies an original of 90.
To find the discount rate from two prices, divide the saving by the original: a drop from 90 to 63 is 27 / 90 = 30%.
To combine an item discount with a whole-basket code, apply the item discount first, then the basket rate to the running total.
Common mistakes
Adding stacked percentages together, which always overstates the saving.
Applying the discount to the tax-inclusive price when the retailer applies it before tax, producing a small mismatch at checkout.
Treating a percentage off an inflated list price as a real saving when the item rarely sells at that price.
Glossary and verification
List price: the pre-discount price. Sale price: the price after the discount. Saving: the difference. Effective discount: the total reduction once every offer is applied.
Verify by multiplying the list price by the remaining factor — 90 x 0.70 should equal the 63 shown.
Verify a stack by applying each factor in turn and comparing with the single effective factor the calculator reports.
Sale cycles and timing a purchase
Most categories discount on a predictable cycle: clothing at end of season, electronics around new model launches, furniture in seasonal sales, and travel outside peak dates.
Knowing the cycle is usually worth more than any single coupon. Waiting six weeks for a seasonal clearance often beats a 10% code today.
Against that, a genuinely scarce item may not return. Weigh the expected saving against the risk of it selling out.
Unit price as the honest comparison
Multibuy and bulk offers are only comparable through unit price — cost per litre, per hundred grams, per sheet. Package sizes are frequently chosen to make direct comparison difficult.
A larger pack at a lower unit price is not a saving if part of it is wasted, which matters for perishables.
Compute the unit price after the discount, not before, or the comparison rewards the deeper-looking discount rather than the cheaper product.
Return policies, warranties, and clearance risk
Clearance and final-sale items frequently carry reduced return rights. A deep discount on something you cannot return is a different proposition from the same discount on a returnable item.
Manufacturer warranties usually survive a discount, but grey-market and refurbished stock may not carry the same cover. Confirm before treating the saving as pure gain.
Where a return window exists, note its length. A short window on a heavily discounted item leaves little time to discover a fault.
Loyalty points, cashback, and the true price
Points and cashback are effectively additional discounts, but only at the rate you can actually redeem them. Points that expire unused are worth nothing.
Convert every reward to its cash value before comparing offers: two percent cashback on a full-price item rarely beats a ten percent discount elsewhere.
Stacking a card cashback with a store code is legitimate and common; just apply them in the order the retailer specifies to avoid one voiding the other.
Budgeting around sales
A discount only saves money on something you intended to buy. Spending fifty to save twenty on an unplanned item is a net outflow of thirty.
Keeping a short list of wanted items turns sale periods into planned purchases rather than impulse ones, and makes the saving real.
Set a maximum you are willing to pay before you see the discount. If the sale price is above it, the percentage is irrelevant.
Stacked and sequential discounts
Two discounts applied one after another never add up: twenty percent off followed by ten percent off leaves seventy-two percent of the original price, a total of twenty-eight percent rather than thirty.
The order does not change the result for pure percentage discounts, but it does when a fixed-value voucher is mixed in.
Fixed amounts applied before a percentage save less than the same voucher applied afterwards, which is why retailers specify the order.
Working in multipliers rather than percentages makes stacked offers straightforward to compare at the till.
Judging whether a deal is real
A discount is only meaningful against a price the item genuinely sold at recently, which is why many jurisdictions regulate reference pricing.
Comparing the sale price with the current price at two other retailers is a faster honesty check than examining the percentage.
Bundle offers can hide a poor unit price, so divide by quantity before comparing with a single-item price.
Delivery charges and return costs belong in the comparison, since they often exceed the discount on smaller purchases.
Timing, price history, and patience
Many categories follow predictable discount cycles, so knowing when a product is normally reduced is worth more than reacting to any single offer.
Price-history tools show whether the current price is genuinely low relative to the past year, which the advertised percentage cannot tell you.
Waiting a short period often costs nothing and reveals whether a price is a real low or simply the usual level dressed up.
Urgency messaging exists to prevent exactly that comparison, so treat a countdown as a reason to slow down rather than speed up.
When this calculator is useful
- Sale shopping
- Comparing coupon vs percentage deals
- Verifying receipts
- Pricing your own products
Frequently asked questions
Is 20% off then 10% off the same as 30% off?
No. Sequential discounts multiply: 0.8 × 0.9 = 0.72, so you pay 72% — a 28% discount.
How do I find the original price from the sale price?
Divide the sale price by (1 − discount/100). A $60 item after 25% off originally cost 60 ÷ 0.75 = $80.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount ÷ 100). A $60 item after 25% off was originally $80.
Is tax charged before or after the discount?
Almost always after, on the reduced price, so the discount lowers your tax as well.
How do I compare a coupon with a percentage discount?
Convert the coupon to a percentage at that specific price: $10 off a $50 item is 20%, but only 5% off a $200 item.
What does 'buy one get one 50% off' work out to?
Across the two items it is a 25% discount overall, assuming both items cost the same.
Can the discount be more than 100%?
No. A 100% discount makes the item free; anything higher is not meaningful, so the calculator caps the input at 100%.
How do I calculate the discount percentage from two prices?
Subtract the sale price from the original, divide by the original, and multiply by 100.
Do two discounts of 20% make 40% off?
No. They multiply to 0.8 x 0.8 = 0.64, a 36% total discount.
Should a coupon be applied before or after a percentage discount?
Applying a fixed-value coupon first saves more. Retailer terms usually dictate the order.
How can I tell if a sale is genuine?
Compare with recent real prices at other retailers rather than the advertised 'was' price.
Is it better to wait for a seasonal sale?
Usually yes for non-urgent purchases — seasonal cycles typically beat individual coupon codes.
How do I compare offers with different pack sizes?
Compare the post-discount unit price — per litre, per hundred grams, or per item.
Can I return a clearance item?
Often not, or on shorter terms. Check the policy before buying, since final-sale rules are common on deep discounts.
How do I value cashback against a discount?
Convert the reward to cash at the rate you can actually redeem, then compare it with the discounted price.
Is a discount always a saving?
Only on something you already intended to buy — otherwise it is spending, not saving.
Do stacked discounts add together?
No. Twenty then ten percent gives twenty-eight percent off in total, not thirty.
How do I tell whether a discount is genuine?
Compare the sale price with current prices elsewhere rather than trusting the advertised percentage.
How do I know if a price is really low?
Check the price history over the past year rather than trusting the advertised percentage.