Discount Calculator

Prepare a successful discount policy with Calcopolis.

Use this discount calculator to find the price after a percentage discount or a fixed-dollar reduction. Choose the discount type, enter the original price and discount, and check the discounted price. In percentage mode, the calculator also shows how much you save in dollars.

How to use the discount calculator

  1. Select Discount type: choose “% off” for a percentage reduction or “fixed amount off” for a dollar reduction.
  2. Enter Price: use the original price before the discount. The form displays monetary amounts in dollars.
  3. Enter Discount: enter a percentage in “% off” mode, or a dollar amount in “fixed amount off” mode. For 20% off, enter 20, not 0.20.
  4. Read Discounted price: this is the original price minus the discount. Percentage mode also displays a separate “Discount” result showing the dollar savings.

Use a price and discount that apply to the same purchase: a per-item price for an item-level discount, or an eligible order total for an order-level discount. The calculator does not determine coupon eligibility, minimum spending requirements, taxes, or shipping charges.

Discount formula and examples

Let P be the original price, D the discount percentage entered as a number, and F the fixed-dollar discount.

Percentage off

Discount amount = P × D / 100

Discounted price = P × (1 − D / 100)

For example, an item priced at $120 with 25% off gives:

  • Discount amount: $120 × 25 / 100 = $30
  • Discounted price: $120 × (1 − 25 / 100) = $90

A 25% discount means you save one-quarter of the original price and pay the remaining 75%.

Fixed amount off

Discounted price = P − F

For the same $120 item, a $25 discount gives a discounted price of $120 − $25 = $95. Your savings equal the fixed discount you entered.

This distinction matters: 25% off and $25 off are equal only when the original price is $100. Above $100, 25% off saves more; below $100, $25 off saves more.

Example with cents: 40% off a camera

A camera costs $184.99 before a 40% discount:

  • Discount amount: $184.99 × 0.40 = $73.996, or $74.00 rounded to cents.
  • Discounted price: $184.99 × 0.60 = $110.994, or $110.99 rounded to cents.

Keep full precision during the calculation and round monetary results at the end. A retailer’s item-level or order-level rounding rules can sometimes produce a one-cent difference.

a man haggling in the bazaar

How to find the discount percentage or original price

The calculator above works forward from an original price and a known discount. If you instead know the sale price, use these rearranged formulas.

Find the discount percentage from two prices

Discount percentage = (Original price − Sale price) / Original price × 100

If an item falls from $120 to $90, the discount percentage is ($120 − $90) / $120 × 100 = 25%. Divide the savings by the original price, not the sale price.

This formula requires an original price greater than zero. Compare prices on the same basis—for example, both before tax or both including the same tax rate.

Find the original price before a discount

Original price = Sale price / (1 − D / 100)

If glasses cost $300 after 60% off, you paid 40% of the original price. The original price was $300 / 0.40 = $750.

You cannot recover the original price from a $0 sale price and a 100% discount: any original price would become zero after 100% off.

Common mistakes when calculating discounts

  • Adding successive discount percentages. An extra 10% off after 20% off usually applies to the reduced price. A $100 item becomes $80, then $72—an overall discount of 28%, not 30%. To calculate this with the form, use the first discounted price as the next original price.
  • Mixing tax-inclusive and tax-exclusive prices. Keep the price basis consistent. Use the sales tax calculator to work between before-tax and after-tax prices, or the reverse sales tax calculator to remove included tax. The discount calculator has no separate tax input; checkout tax treatment depends on the applicable rules.
  • Entering an excessive discount. For an ordinary sale, use a percentage from 0 to 100, or a fixed discount no greater than the original price. The formulas produce a negative price beyond those limits, which is not a normal amount payable.
  • Treating savings as the complete checkout total. Shipping, fees, taxes, exclusions, and coupon limits may change what you ultimately pay.

Using discounts to compare offers and plan promotions

For shopping comparisons, calculate the actual price you would pay rather than judging an offer by its percentage alone. A larger discount on a higher starting price can still leave you paying more.

For a business promotion, test the selling price against your costs before choosing a discount. Suppose a product sells for $100 and costs $60. Its gross profit is $40. After 20% off, the selling price is $80 and gross profit is $20: the discount has cut gross profit per unit in half, assuming the product cost is unchanged and excluding other expenses.

Quantity, bundle, trade, and loyalty offers can all involve discounts, but their eligibility rules sit outside this calculator. Once you know the eligible price and reduction, use the appropriate percentage or fixed-amount mode.

Related pricing calculators

Need customers to estimate prices using your own quantity tiers or discount rules? Calcopolis lets you build a custom product pricing calculator for your website, helping visitors explore eligible offers before requesting a quote.