Toolphy

Percent Off Calculator

Enter an original price and a percentage discount to see the sale price and how much you save — or switch to reverse mode to recover the original price from a discounted one.

How to Use the Percent Off Calculator

The Percent Off Calculator answers the two questions shoppers and sellers ask most often about discounts: what will I actually pay, and how much am I saving. It also works backwards, so if you only know the discounted price and the percentage, it can recover the original ticket price. Everything runs instantly in your browser, with no sign-up and nothing uploaded.

  1. Choose a mode. Use the tabs at the top to switch between Price After Discount and Find Original Price. In the first mode you know the original price and the discount and want the sale price; in the second you know the sale price and the discount and want the price before the markdown.

  2. Enter your numbers. For the discount mode, type the original price, for example 120, and the percentage off, for example 25. For the reverse mode, enter the sale price you actually paid, for example 90, and the discount that was applied, for example 25.

  3. Read the result. The tool shows the sale price or the original price, the amount saved (or, in reverse mode, the discount amount implied), and the exact formula with your numbers filled in. Example: 25% off $120 gives a sale price of $90 and a saving of $30; if $90 is the result of 25% off, the original price was 90 ÷ 0.75 = $120.

  4. Copy the answer. Press Copy result to send the figure and its formula to your clipboard, ready for a shopping list, a spreadsheet or a message to a friend.

What Does “Percent Off” Mean?

A percentage off is a reduction applied to an original price. When a retailer offers 25% off a $120 item, the discount amount is 120 × 25 ÷ 100 = $30, and the sale price is 120 − 30 = $90. The formula in full is sale price = original price × (1 − percent ÷ 100). The complement of the discount — 100% minus the percentage off — is the fraction of the original price you still pay, which is why 25% off means paying 75% of the tag. The reverse calculation is less obvious but equally useful. If you know the sale price and the discount, you cannot simply add the percentage back, because the discount was calculated on the original price, not on the sale price. You must divide: original price = sale price ÷ (1 − percent ÷ 100). For a $90 sale price after 25% off, the original was 90 ÷ 0.75 = $120. Adding 25% to $90 would wrongly give $112.50. Understanding both directions matters because discounts are rarely the only factor in a purchase. Knowing the original price lets you judge whether a “deal” is genuine, and knowing the sale price lets you budget accurately. This calculator shows the formula at every step so you can verify the arithmetic yourself and build the habit of checking listed discounts.

Common Applications

1. Retail shopping: A jacket marked $120 is advertised at 25% off. The calculator confirms you pay $90 and save $30, so you can compare it with a rival store selling the same jacket for $95.

2. Seasonal sales: During a 40% off sale, a $250 item drops to $150 — a saving of $100 — which makes it easy to prioritise what is genuinely worth buying.

3. Reverse price checks: A checkout shows a final price of $68 after an unspecified discount that you later learn was 15%. Reverse mode reveals the original price was about $80.

4. Budgeting: A student planning a $200 grocery run with a 10% member discount knows the total will be $180, so they can decide whether the trip fits their weekly budget.

5. Business and pricing: A shop owner trialling a 30% introductory discount on a $45 product can confirm the promotional price is $31.50 and estimate the margin impact before launch.

Percentage Off vs Percentage Points

A discount of “25% off” is a relative reduction, not a number of percentage points. If an item is reduced from $120 to $90, the price fell by 25% — but if you describe the new price as 75% of the old one, that is a statement about the proportion you pay, not a second discount. Keep the two framings separate to avoid double-counting a markdown.

How to Stack Multiple Discounts

Discounts rarely add up the way people expect. A further 10% off an already discounted $90 price gives $81, not 35% off the original $120 (which would be $78). To combine two sequential discounts, multiply the remaining fractions: 0.75 × 0.90 = 0.675, so the final price is 67.5% of the original. Always apply additional percentages to the running price, not the original one.

Guides

Frequently Asked Questions - FAQ

Is my data safe using this tool?

Yes. Every calculation runs locally in your browser with JavaScript. No prices or percentages are transmitted and nothing is stored on a server.

How do I calculate the sale price from a percentage off?

Multiply the original price by (1 − percent ÷ 100). For 25% off $120, the sale price is 120 × 0.75 = $90, and the saving is $30.

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

Divide the sale price by (1 − percent ÷ 100). If you paid $90 after a 25% discount, the original price is 90 ÷ 0.75 = $120.

Why can’t I just add the discount back to the sale price?

Because the discount was calculated on the original, higher price. Adding 25% to $90 gives $112.50, but the true original was $120. Dividing by the remaining fraction is the correct reverse method.

Can I use this for discounts above 100%?

No. A discount of 100% makes an item free, and anything above 100% would imply a negative price, so the tool limits the discount to between 0 and 100%. Reverse mode requires a discount strictly below 100%.

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