Calculate the percentage discount between an original price and a sale price.
Please enter valid positive numbers.
Original Price:$0.00
Sale Price:$0.00
Total Savings:$0.00
Discount Rate:0%
function calculateDiscountRate() {
var originalInput = document.getElementById('originalPrice');
var saleInput = document.getElementById('salePrice');
var errorMsg = document.getElementById('errorMsg');
var resultBox = document.getElementById('resultBox');
var originalPrice = parseFloat(originalInput.value);
var salePrice = parseFloat(saleInput.value);
// Validation: Ensure inputs are numbers and Original Price is positive
if (isNaN(originalPrice) || isNaN(salePrice) || originalPrice <= 0 || salePrice < 0) {
errorMsg.style.display = 'block';
resultBox.style.display = 'none';
return;
}
errorMsg.style.display = 'none';
// Core Calculation Logic
var savings = originalPrice – salePrice;
var discountRate = (savings / originalPrice) * 100;
// Handle price increase (negative discount)
var isIncrease = false;
if (savings < 0) {
isIncrease = true;
// For increase, the formula is still valid, showing negative savings and negative discount rate (markup)
}
// Formatting Results
document.getElementById('displayOriginal').innerHTML = '$' + originalPrice.toFixed(2);
document.getElementById('displaySale').innerHTML = '$' + salePrice.toFixed(2);
if (isIncrease) {
document.getElementById('displaySavings').innerHTML = '-$' + Math.abs(savings).toFixed(2) + ' (Price Increase)';
document.getElementById('displayRate').innerHTML = '-' + Math.abs(discountRate).toFixed(2) + '%';
document.getElementById('displayRate').style.color = '#e74c3c'; // Red for price hike
} else {
document.getElementById('displaySavings').innerHTML = '$' + savings.toFixed(2);
document.getElementById('displayRate').innerHTML = discountRate.toFixed(2) + '%';
document.getElementById('displayRate').style.color = '#27ae60'; // Green for discount
}
resultBox.style.display = 'block';
}
How to Use the Discount Rate Calculator
Whether you are a shopper trying to determine the percentage off a clearance item, or a merchant setting up a sale strategy, understanding the specific Discount Rate is essential. This tool determines the exact percentage decrease from an original list price to a final selling price.
The Discount Rate Formula
To calculate the discount rate manually, you compare the difference between the original price and the sale price against the original price. The formula is:
Discount Rate (%) = ((Original Price – Sale Price) / Original Price) × 100
For example, if a jacket is listed at $100 and is on sale for $80:
Calculate the savings: $100 – $80 = $20.
Divide the savings by the original price: 20 / 100 = 0.20.
Multiply by 100 to get the percentage: 0.20 × 100 = 20% Discount Rate.
Why Calculate the Discount Rate?
Smart Shopping: Retailers often use signs like "$20 Off" or "Save $50". Converting these fixed amounts into a percentage rate helps you compare deals across different price points.
Business Pricing: For store owners, calculating the discount rate is crucial for margin analysis. It ensures that your markdown strategy drives sales without eroding all profit.
Invoicing: In B2B transactions, "Early Payment Discounts" (e.g., 2/10 net 30) are effectively discount rates applied to invoices to encourage speedier payment.
Common Discount Terminology
List Price (MSRP): The suggested retail price of a product before any deductions.
Net Price: The final price paid after the discount rate has been applied.
Markdown: A reduction in the selling price, often expressed as a percentage rate.
Note: While in finance, "Discount Rate" can refer to the interest rate used in Discounted Cash Flow (DCF) analysis to determine the present value of future cash flows, this calculator focuses on the retail definition regarding price reduction percentages.