Calculate a Discount: 25% Off, Was/Now and Stacked (Free)

The discount formula

Convert the percentage to a decimal by dividing by 100, then use two lines:

• Savings = original price × discount %
• Sale price = original price − savings, or original price × (1 − discount %)

For $84 and 25 percent: 84 × 0.25 = $21.00 saved, and 84 − 21 = $63.00. The one-step version, 84 × 0.75 = $63, is faster once you know it: subtract the discount from 1 first (1 − 0.25 = 0.75) and multiply once.

Quick mental checks: 10 percent is the price with the decimal point moved one place, 50 percent is half, and 25 percent is half of half. For $84, 10 percent is $8.40, so 30 percent is $25.20.

Finding the real percent off from a was and now price

Tags often show only two prices. The percentage is the drop divided by the original: (original − sale) ÷ original × 100. With an original of $129 and a price you pay of $103.20, the saving is $25.80 and 25.80 ÷ 129 = 0.20, so it is 20 percent off. In the calculator, use the Find % off tab, enter both prices and the result appears below them.

Only compare against a real recent price. A high "was" price that was never charged makes any percentage look big, so check the price history or another store before you trust it.

Stacked discounts are not added together

When a store takes 20 percent off and then a coupon takes another 10 percent, the discounts apply one after the other, not together. On a $120 item, 20 percent off is $96.00 and 10 percent off that is $86.40. Total savings are $33.60, which is 28 percent, not 30. The Stacked tab in the calculator lists each step, and it also shows what happens if the order changes: percentage-off coupons taken first leave a smaller dollar coupon a larger share of the price.

A fixed-dollar coupon and a percentage coupon are the case where order matters most, so check the store's terms for which is applied first.

Sales tax and quantity

In most US states sales tax is charged on the discounted price, so a $63 jacket at an 8 percent rate costs 63 × 1.08 = $68.04. Rules differ by state and by coupon type (a manufacturer's coupon can be taxed differently from a store discount), so treat the calculator as an estimate and check the receipt. The calculator has an Add sales tax option and a quantity box, so buying three of the same item at 25 percent off is one line: enter the quantity and read the total.

For a broader guide to percentages see How to Calculate a Percentage.

Comparing offers that look different

Stores present savings in several ways, and the best deal is not always the largest number. A $30 coupon off a $120 item equals 25 percent, while 30 percent off a $90 item saves $27. Buy-one-get-one at half price on a $40 item saves $10 on two, or 12.5 percent overall.

• Divide the amount saved by the original total to compare offers fairly.
• Check minimum spend and exclusions on coupons before you rely on them.
• Include shipping and tax in the final price.
• Remember that a price you would not pay without the sale is not a saving.

To understand how a rise and fall compare, percentage increase and decrease shows why a 20 percent rise is not undone by a 20 percent fall, and calculating sales tax covers the final charge at checkout.

Quick mental checks

Ten percent is one decimal place to the left, so 10 percent of $84 is $8.40. Twenty percent is double that, and 25 percent is a quarter. Use these anchors to sanity-check the calculator.

A short practice set

Try these to check your method. A $60 jacket at 30 percent off costs $42, saving $18. A $250 monitor at 15 percent off costs $212.50. A $80 pair of shoes at 40 percent off then another 10 percent off costs $43.20, not $40. Work out each one in your head first and then confirm with a calculator. The final example shows why stacked offers deserve a second look, because the second percentage applies to the already reduced price.

Build the habit of checking the final total, not the headline percentage. Add delivery, tax and any membership fee, then divide by the number of items. A smaller discount on a product you truly need beats a bigger one on something you would not buy at full price. Keep a short note of prices you have seen over the last months, which makes it easier to tell a real bargain from a marketing label.

Step-by-step

Common mistakes to avoid

Pro tips

Frequently asked questions