About This Tool
Getting the best deal means knowing exactly how much you save. This discount calculator takes the guesswork out of sale shopping, coupon stacking, and clearance math. Enter any original price and discount percentage to instantly see the final price, the dollar amount saved, and how the discount compares visually to the original cost. Beyond simple single-discount calculations, this tool includes a multi-discount stacking feature. Many retailers and coupon platforms let you combine discounts -- for example, a 20% store-wide sale plus a 10% loyalty coupon. Most shoppers assume those two discounts add up to 30% off, but that is incorrect. Each discount applies sequentially to the already-reduced price, so a 20% + 10% stack actually saves you 28%, not 30%. The stacking calculator breaks down each step so you see exactly where every dollar goes. A quick reference table updates in real time to show savings for common discount percentages (10%, 15%, 20%, 25%, 30%, 40%, 50%, 75%) based on your entered price. This is useful when comparing multiple deals side by side. Your data stays private -- nothing is stored or shared.
How to Calculate a Discount
The standard discount formula has two steps:
- Find the savings: Multiply the original price by the discount percentage (as a decimal). For a $120 item at 25% off: $120 * 0.25 = $30 saved.
- Find the final price: Subtract the savings from the original price. $120 - $30 = $90 final price.
As a single formula: Final Price = Original Price * (1 - Discount / 100).
This tool handles both steps automatically and also provides the bar chart comparison so you can visually gauge the size of the savings relative to the original cost.
How Discount Stacking Works
Discount stacking (also called compounding discounts) applies each discount one after another to the progressively reduced price. The key insight is that the second discount applies to the already discounted price, not the original.
Example: $100 item with 20% off, then 10% off
- Step 1: $100 * 0.80 = $80 (after 20% off)
- Step 2: $80 * 0.90 = $72 (after 10% off the $80)
- Total saved: $28, which is 28% of the original -- not 30%
The mathematical formula for stacked discounts is: Final Price = Original * (1 - d1/100) * (1 - d2/100) * ... * (1 - dn/100).
The more discounts you stack, the larger the gap between the combined percentage and the effective percentage. Three discounts of 10% each total 30% combined but only 27.1% effective savings.
Common Discount Scenarios
Discounts appear in many different forms across retail and business contexts:
- Seasonal Sales: Black Friday, holiday clearance, and end-of-season sales typically range from 20% to 70% off.
- Coupon Stacking: Many stores let you combine a manufacturer coupon with a store coupon. Understanding how these stack helps you calculate the true savings.
- Employee Discounts: Typical employee discounts range from 10% to 30%. Some companies stack this on top of existing sales.
- Volume Discounts: Buying in bulk often triggers tiered pricing. For instance, 5% off 10+ units, 10% off 50+ units, 15% off 100+ units.
- Loyalty or Membership Discounts: Credit card rewards, store memberships (like Amazon Prime), and points programs effectively act as additional discounts on purchases.
- Negotiated Discounts: B2B contracts often involve negotiated percentage reductions from list price. Use this calculator to verify the math on proposals.
Discount vs. Markup: The Retailer Perspective
Shoppers see discounts from one side, but retailers must consider the math from both directions. A 50% discount does not mean the retailer loses 50% of their profit -- it depends on their margin.
If a retailer buys an item for $40 and normally sells it for $100 (60% gross margin), a 30% discount brings the price to $70. They still earn $30 profit ($70 - $40 cost), preserving a 42.9% margin. But a 60% discount drops the price to $40, wiping out all profit.
This is why clearance discounts have limits. Retailers calculate the maximum discount they can offer while still covering their cost of goods, shipping, and overhead. The break-even discount percentage equals the gross margin percentage. Anything beyond that sells at a loss.
Tips for Maximizing Savings
A few strategies to get the most out of discounts:
- Compare effective percentages: "Buy 2 Get 1 Free" equals a 33.3% discount on each item. Compare that to a flat 30% off to see which deal is better.
- Account for sales tax: Discounts reduce the taxable amount, so you save on tax too. A $100 item at 20% off in a state with 8% sales tax costs $86.40 total, not $88.
- Watch for "up to" language: "Up to 50% off" means the maximum discount is 50%, and most items will be discounted less. Always check individual item prices.
- Calculate per-unit cost: For multi-pack deals, divide the total price by the number of units to compare against buying individually.
- Consider the original price: A 70% discount on an inflated price may still be more expensive than a 10% discount from a competitor with lower base pricing.
Frequently Asked Questions
How do I calculate 20% off a price?
Multiply the price by 0.20 to get the discount amount, then subtract it from the original. For example, 20% off $75: $75 * 0.20 = $15 discount, so you pay $75 - $15 = $60. Alternatively, multiply by 0.80 directly: $75 * 0.80 = $60.
Is 20% off plus 10% off the same as 30% off?
No. Stacked discounts always result in less savings than combining the percentages. With a $100 item:
- 30% off: $100 * 0.70 = $70 (you save $30)
- 20% off then 10% off: $100 * 0.80 = $80, then $80 * 0.90 = $72 (you save $28)
The stacked approach saves $2 less because the second discount applies to the reduced price, not the original.
How do I figure out the original price before a discount?
Divide the sale price by (1 minus the discount as a decimal). If an item costs $60 after 25% off: $60 / (1 - 0.25) = $60 / 0.75 = $80 original price. This is called reverse discount calculation.
What is "Buy One Get One 50% Off" as a total discount?
Assuming both items are the same price, you pay 100% for the first item and 50% for the second. Total cost is 150% of one item price for two items. That equals a 25% discount overall. For example, two $40 shirts: you pay $40 + $20 = $60 instead of $80, saving $20 (25%).
Does the order of stacked discounts matter?
Mathematically, no. A 20% discount followed by a 15% discount gives the same final price as 15% first then 20%. Multiplication is commutative: 0.80 * 0.85 = 0.85 * 0.80 = 0.68. The final price is 68% of the original regardless of order. However, some store systems may process discounts differently or cap combinations, so always verify the final total.
How do I calculate the discount percentage from two prices?
Use this formula: Discount % = ((Original - Sale Price) / Original) * 100. For example, an item dropped from $89.99 to $62.99: ($89.99 - $62.99) / $89.99 * 100 = 30.0%. This tells you the exact percentage markdown between the two prices.