What is a discount calculator?

A discount calculator works out how much you save when a price is reduced by a percentage. Type the original price and the discount, and you instantly see the sale price and the amount you keep in your pocket. You can also work backward: enter a sale price and a discount to find what the item cost before the sale, or enter two prices to find out how big the discount really is.

Sales signs make savings look simple, but the math gets harder when you stack coupons on top of a markdown, add sales tax, or want to know whether "40% off" on a higher price beats "30% off" on a lower one. This tool does all of that in one place.

The formulas behind it

• Sale price = original price × (1 − discount ÷ 100).
• You save = original price − sale price.
• Original price = sale price ÷ (1 − discount ÷ 100).
• Discount % = (original price − sale price) ÷ original price × 100.
• Two discounts in a row = original × (1 − first ÷ 100) × (1 − second ÷ 100).
• Sales tax = price after discounts × tax rate ÷ 100.

For a quick mental check, multiply by what you pay instead of what you save. A 30% discount means you pay 70% of the price, so you can multiply the original price by 0.70 directly.

How to use this calculator

1. Pick what you want to find: the sale price, the original price, or the discount percentage.
2. Fill in the two numbers. The labels change to match your choice.
3. For a sale price, you can add an extra discount (such as a coupon) and your local sales tax. Leave them at 0 if they do not apply.
4. Press Calculate or the Enter key. The result appears at the top, with a breakdown and a table of common discounts for the same price.

Worked examples

Sale price. A jacket costs $120 and is 30% off. You save $120 × 0.30 = $36, so you pay $84. Multiplying $120 × 0.70 gives the same answer.

Original price. You paid $84 for a jacket that was 30% off. The original price was $84 ÷ 0.70 = $120. Notice that you cannot simply add 30% to $84, because 30% of $84 is only $25.20 and would give $109.20.

Discount percentage. A pair of shoes drops from $80 to $60. The saving is $20, and $20 ÷ $80 = 25% off.

Sale price table

This table shows the price after common discounts on typical original prices.

Original price	10% off	20% off	30% off	50% off
$20	$18.00	$16.00	$14.00	$10.00
$50	$45.00	$40.00	$35.00	$25.00
$100	$90.00	$80.00	$70.00	$50.00
$250	$225.00	$200.00	$175.00	$125.00
$500	$450.00	$400.00	$350.00	$250.00

Why two discounts do not add up

When a store takes 20% off and then you use a 10% coupon, the total discount is not 30%. The second discount applies to the already reduced price, not to the original. The table shows what happens on a $100 item.

Two discounts	Price of a $100 item	Real total discount
10% then 10% off	$81.00	19%
20% then 10% off	$72.00	28%
20% then 20% off	$64.00	36%
30% then 20% off	$56.00	44%
40% then 20% off	$48.00	52%
50% then 20% off	$40.00	60%

The bigger the two numbers, the bigger the gap between the simple sum and the real result. Always run the numbers before you assume a stacked offer is as good as it sounds.

Do not forget sales tax

In the United States, sales tax is usually added after the discount is applied, so the tax is calculated on the lower price. That means a discount also lowers the tax you pay. Rates differ by state and by city, so use the field above to enter your local rate. Some places also charge tax on the original price for certain coupons, so check your receipt if the totals do not match.

Quick mental math for common discounts

You do not always have a phone in your hand at the store. These shortcuts let you estimate a sale price in a few seconds.

• 10% off: move the decimal point one place to the left and subtract. 10% off $65 is $65 − $6.50 = $58.50.
• 20% off: find 10%, double it, and subtract. 20% off $65 is $65 − $13 = $52.
• 25% off: divide by 4 and subtract. 25% off $80 is $80 − $20 = $60.
• 50% off: divide by 2.
• 75% off: divide by 4 and pay that amount.
• 15% off: take 10%, add half of it, and subtract the total. 15% off $60 is $60 − ($6 + $3) = $51.

Where discounts show up in everyday life

Percent discounts appear well beyond clothing sales. Grocery stores use them for coupons and clearance items, travel sites use them for early booking offers, and many subscriptions advertise a lower price when you pay for a year in advance. Businesses also use discounts for bulk orders, loyalty programs, students, seniors and military members. In each case the same rule applies: the percentage is taken from the price before the discount, and a second offer is taken from the new price. Learning to check that quickly helps you spot real bargains and avoid offers that sound better than they are.

Discounts are also useful in the other direction. If you sell products, the calculator helps you see what a promotion will do to your price and how much income you give up for each sale, which is a useful check before you advertise a deal.

Smart ways to shop sales

• Compare final prices, not percentages. 20% off a $100 item is a better deal than 40% off a $300 item you do not need if the second price is still higher than you would pay elsewhere.
• Check the original price. A discount is only a real saving if the former price was a price the store actually charged.
• Check unit price. A bigger pack on sale is not always cheaper per item.
• Wait for stacking offers. Coupons, loyalty points and card rewards can add to a sale, but read the terms.
• Set a budget first. A good sale on something you did not plan to buy is still money spent.

Common mistakes to avoid

• Adding discounts together. 20% plus 10% is 28% off, not 30%.
• Adding the percentage back to the sale price. To find the original price you must divide, not add.
• Using the wrong base. A discount is always a percentage of the original price.
• Ignoring tax and shipping. They change the final cost and sometimes cancel a small saving.

Frequently asked questions

How do I calculate a 20% discount?

Multiply the price by 0.80. For example, 20% off $50 is $50 × 0.80 = $40. You save $10.

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

Divide the sale price by one minus the discount as a decimal. If $60 is the price after 25% off, the original price was $60 ÷ 0.75 = $80.

Is 50% off the same as buy one get one free?

On two identical items, yes: you pay for one and get two, so each costs half. It is not the same if you only want one item, because buy one get one free needs two purchases.

Does the calculator include sales tax?

Yes, if you enter a rate. Tax is added after the discounts. Leave the field at 0 for a price without tax.

Is my information stored?

No. Everything is calculated in your browser. Nothing you type is sent to our server or saved.

Helpful resources

• State and Local Sales Tax Rates from the Tax Foundation, to find the rate for your state
• Our Percentage Calculator for any percent increase, decrease or change
• Our Savings Goal Calculator, to turn the money you save on sales into a plan

This calculator provides estimates for general information only. Store prices, taxes and fees may differ. See our Terms & Disclaimer.