Percent Off Calculator

Finding the sale price with the percent off calculator

When a store advertises a discount, the amount you save is a percentage of the original price, and the sale price is what remains after that amount is removed. Written out, the formulas are:

Worked example. A $45 jacket is marked 30% off. The amount saved is 45 x (30 / 100) = 45 x 0.30 = $13.50. The sale price is 45 - 13.50 = $31.50. So a $45 jacket at 30% off costs $31.50 at the register, and the discount itself is worth $13.50.

Finding the percent off from two prices

Sometimes a store shows an original price and a sale price side by side without stating the percent off directly, or a receipt just shows what you paid versus the listed price. To recover the percent off, first find the amount saved, then express that amount as a percentage of the original price:

Worked example. A $100 jacket is on sale for $75. The amount saved is 100 - 75 = $25. The percent off is (25 / 100) x 100 = 25%. So a jacket marked down from $100 to $75 is a 25% off sale, not a 75% off sale, since 75 is the price you pay, not the discount.

Stacking discounts does not add up the way it looks

A common shopping mistake is assuming that a 20% off coupon plus an extra 10% off at checkout equals 30% off. It does not, because the second discount is calculated on the already-reduced price, not on the original price. Percent reductions applied one after another multiply the remaining fraction of the price, they do not simply add together.

Worked example. A $100 item first gets 20% off: 100 x (1 - 0.20) = 100 x 0.80 = $80. Then an extra 10% off is applied to that $80, not the original $100: 80 x (1 - 0.10) = 80 x 0.90 = $72. The final price is $72, a total saving of $28, which works out to 28% off the original price, not the 30% off it might look like at first glance. The gap grows the more discounts are stacked, so always apply each one to the price that came before it, never to the original price twice.

Common mixups

• Confusing the percent off with the price paid. A 25% off sale means you pay 75% of the original price, not 25% of it. Reading the percent off as the price paid, instead of the amount removed, is the most frequent mistake on a sale sign.
• Adding stacked discounts instead of multiplying the remaining fraction. As shown above, 20% off plus 10% off is 28% off total, not 30% off, because the second discount shrinks a smaller number.
• Forgetting that tax is usually applied after the discount. The sale price calculated here does not include sales tax; most stores add tax to the discounted price at checkout, not to the original price.
• Assuming a bigger percent off is always a bigger dollar saving. A 50% off $20 item saves $10, while a 20% off $100 item saves $20. The dollar amount saved depends on the original price just as much as the percent off.

Tips for entering values

Enter the original price and sale price as plain numbers without a currency symbol, for example 45 rather than $45.00; the calculator formats the result with two decimal places automatically. Percent off should be entered as a whole number or decimal out of 100, not a decimal fraction of 1, so a 30 percent discount is entered as 30, not 0.3. If a price was copied with a dollar sign, comma, or extra spacing from a receipt or website, remove those characters first, since the field expects a plain number to calculate correctly.

Converting a fraction discount into a percent

Some sales are advertised as a fraction off rather than a percent, such as "1/3 off" or "a quarter off," and this calculator needs a percent, not a fraction, in the percent off field. Converting is one division: multiply the fraction by 100. A third off is 1 ÷ 3 × 100 ≈ 33.33 percent off, and a quarter off is 1 ÷ 4 × 100 = 25 percent off. Worked example. A $60 item marked "a third off" is entered here as 60 and 33.33, giving an amount saved of 60 × (33.33 / 100) ≈ $20.00 and a sale price of about $40.00, which matches the more direct way of checking a third off $60 by dividing 60 by 3.

Verifying the calculator's output by hand

The three numbers a discount calculation produces, original price, amount saved, and sale price, always satisfy one simple check: original price minus amount saved equals sale price, and amount saved plus sale price equals the original price. For the $45 jacket at 30% off example above, 45 − 13.50 = 31.50 and 13.50 + 31.50 = 45, both checks passing. Running this quick addition or subtraction after any result is a fast way to catch a typo in the original price or percent off before trusting the number for a real purchase decision.

Reading edge-case results

A calculated percent off of 0% means the sale price and original price are identical, so no actual discount is being applied even if a sale is advertised; entering the same number in both price fields is a quick way to confirm this reads as 0% rather than an error. A percent off of exactly 100% means the amount saved equals the entire original price, so the sale price comes out to $0.00, the mathematically correct result for a fully complimentary item. This differs from a percent off entered as anything above 100%, which this calculator rejects outright, since a discount cannot remove more value than the item was worth in the first place.

Common deals worked out to the cent

The tables work more sales through the two formulas above, one set with round-dollar prices and one with cents. Each deal reads as the percent off, then the price, so 30 off 50 means 30% off a $50 item. Find the row closest to your own price and read the saving straight off, then use the calculator for anything in between.

Other names for the same calculator

This tool answers to several names: a percent off calculator, a percentage off calculator, an off percent calculator, or simply a discount calculator, a sale price calculator, or a discount price calculator, since all of them describe the same original-price-and-percent-off math. Because it also works out the percentage off when given two prices instead, it functions as a percent off calculator with two prices, a reverse discount calculator, or a what percent off calculator whenever the missing number is the percentage rather than the sale price. The formulas behind both directions are sometimes searched for directly too: the sale price formula and the percent off formula shown above are exactly what a search for how to calculate percent off by hand is looking for. Because a discount is really just a price decreasing from one number to a smaller one, the same two-step process also doubles as a percent decrease calculator, useful any time the size of a drop between two numbers matters, not only for a sale price.

Because a store rarely advertises just one discount, this also covers a stacked discount calculator or a double discount calculator for a coupon plus an extra checkout discount, working out the real combined percentage off rather than a simple addition. The amount actually removed from a price is what an amount saved calculator, a discount amount calculator, or a markdown calculator returns, while the number left to pay is what a final price after discount calculator gives back. Whether the sale in question is a clearance discount calculator scenario, a coupon discount calculator situation, or a general percentage discount calculator lookup, the same two formulas above cover it: enter what is known, and the calculator fills in whichever number, sale price, amount saved, or percent off, is missing.