Discount Calculator
Calculate sale prices and savings from percentage discounts with instant precision. Whether you're shopping during a major sale event, comparing deals between stores, planning retail pricing strategies, or calculating wholesale discounts, this tool helps you understand exactly how much you'll save and what you'll pay.
Understanding Discounts
A discount reduces the original price by a specified percentage. Understanding how discounts work helps you make smarter purchasing decisions, recognize truly good deals versus marketing gimmicks, and calculate your actual savings. Many shoppers overestimate their savings because they don't understand how discount math works.
Discount Formulas
| Calculation | Formula | Example (20% off $100) |
|---|---|---|
| Discount amount | Original × (Discount% / 100) | $100 × 0.20 = $20 |
| Sale price | Original - Discount amount | $100 - $20 = $80 |
| Sale price (direct) | Original × (1 - Discount% / 100) | $100 × 0.80 = $80 |
| Finding discount % | ((Original - Sale) / Original) × 100 | (($100 - $80) / $100) × 100 = 20% |
Discount Examples by Category
| Original | Discount | You Save | Final Price | Category |
|---|---|---|---|---|
| $100 | 20% | $20.00 | $80.00 | Clothing |
| $50 | 30% | $15.00 | $35.00 | Electronics |
| $200 | 50% | $100.00 | $100.00 | Furniture |
| $75 | 15% | $11.25 | $63.75 | Books |
| $299 | 25% | $74.75 | $224.25 | Appliances |
| $1,200 | 40% | $480.00 | $720.00 | Large purchase |
Stacking Multiple Discounts
When stores offer "additional" discounts, they apply sequentially—not additively. This is a crucial concept that affects your actual savings:
| Step | Calculation | Result | Total Discount |
|---|---|---|---|
| Original price | $100 | $100 | 0% |
| 20% off | $100 × 0.80 | $80 | 20% |
| Additional 10% off | $80 × 0.90 | $72 | 28% (not 30%) |
Real-World Discount Scenarios
Clearance Sales: Items marked down 70% are often older inventory. Calculate whether the final price represents good value for the product's condition and usefulness.
Buy One Get One: "BOGO 50% off" on two $40 items means you pay $60 total ($40 + $20), not $40. That's 25% off each item, not 50%.
Member Discounts: Store credit cards often offer 10-15% off. Calculate whether the savings outweigh potential interest charges if you carry a balance.
Coupons: Percentage-off coupons typically apply before tax, while dollar-off coupons may apply after. Know your store's policy.
Implementation
``javascript
function calculateDiscount(originalPrice, discountPercent) {
const discountAmount = originalPrice * (discountPercent / 100);
const salePrice = originalPrice - discountAmount;
const pricePercentage = 100 - discountPercent;
return {
originalPrice: originalPrice.toFixed(2),
discountPercent: discountPercent + '%',
discountAmount: discountAmount.toFixed(2),
salePrice: salePrice.toFixed(2),
youPay: pricePercentage + '% of original'
};
}
function stackDiscounts(originalPrice, discounts) {
let currentPrice = originalPrice;
for (const discount of discounts) {
currentPrice = currentPrice * (1 - discount / 100);
}
const totalSaved = originalPrice - currentPrice;
const effectiveDiscount = (totalSaved / originalPrice) * 100;
return { finalPrice: currentPrice.toFixed(2), effectiveDiscount: effectiveDiscount.toFixed(2) + '%' };
}
``
Smart Shopping Tips
Compare unit prices when discounts are involved. A 20% discount on a larger size may still cost more per unit than a smaller size at full price. Always calculate the actual price you'll pay and compare across options.