body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
}
.calculator-wrapper {
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.calc-title {
text-align: center;
margin-bottom: 25px;
color: #2c3e50;
font-size: 24px;
font-weight: 700;
}
.input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 20px;
}
@media (max-width: 600px) {
.input-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 5px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
font-size: 14px;
color: #495057;
}
.input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.15s ease-in-out;
}
.input-group input:focus {
border-color: #007bff;
outline: none;
}
.calc-btn {
display: block;
width: 100%;
padding: 14px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: 600;
cursor: pointer;
transition: background-color 0.15s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #0056b3;
}
.results-section {
margin-top: 30px;
display: none;
background-color: #ffffff;
border: 1px solid #dee2e6;
border-radius: 6px;
padding: 20px;
}
.result-row {
display: flex;
justify-content: space-between;
align-items: center;
padding: 12px 0;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 500;
color: #6c757d;
}
.result-value {
font-weight: 700;
font-size: 18px;
color: #2c3e50;
}
.highlight-result {
background-color: #e8f4fd;
padding: 15px;
border-radius: 6px;
margin-bottom: 15px;
border-left: 5px solid #007bff;
}
.highlight-result .result-label {
color: #0056b3;
display: block;
font-size: 14px;
text-transform: uppercase;
letter-spacing: 0.5px;
margin-bottom: 5px;
}
.highlight-result .result-value {
font-size: 28px;
color: #007bff;
}
.content-section {
margin-top: 50px;
}
.content-section h2 {
font-size: 22px;
color: #2c3e50;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 30px;
}
.content-section h3 {
font-size: 18px;
color: #34495e;
margin-top: 25px;
}
.content-section p {
margin-bottom: 15px;
}
.content-section ul {
margin-bottom: 15px;
padding-left: 20px;
}
.formula-box {
background-color: #f1f3f5;
padding: 15px;
border-left: 4px solid #6c757d;
font-family: monospace;
margin: 15px 0;
}
function calculateRateOfSale() {
// Get inputs
var unitsSoldStr = document.getElementById('totalUnitsSold').value;
var weeksStr = document.getElementById('timePeriodWeeks').value;
var storesStr = document.getElementById('numberOfStores').value;
var inventoryStr = document.getElementById('currentInventory').value;
// Convert to numbers
var unitsSold = parseFloat(unitsSoldStr);
var weeks = parseFloat(weeksStr);
var stores = parseFloat(storesStr);
var inventory = parseFloat(inventoryStr);
// Validation
if (isNaN(unitsSold) || isNaN(weeks) || isNaN(stores) || weeks <= 0 || stores 0) {
weeksCover = inventory / weeklyROS;
weeksCoverText = weeksCover.toFixed(1) + " Weeks";
} else if (inventory > 0) {
weeksCoverText = "> 52 Weeks (Stagnant)";
} else {
weeksCoverText = "0 Weeks";
}
// Display Results
document.getElementById('resultsContainer').style.display = 'block';
document.getElementById('resWeeklyROS').innerHTML = weeklyROS.toFixed(1) + " Units / Week";
document.getElementById('resPerStore').innerHTML = rosPerStore.toFixed(1) + " Units";
document.getElementById('resDaily').innerHTML = dailySales.toFixed(1) + " Units / Day";
document.getElementById('resWeeksCover').innerHTML = weeksCoverText;
}
How to Calculate Rate of Sale in Retail
Understanding Rate of Sale (ROS) is fundamental to effective retail inventory management, merchandising, and supply chain planning. Unlike simple revenue metrics, ROS focuses on the velocity at which physical units move through your business, allowing you to compare performance across different products, categories, or store locations regardless of their price points.
What is Rate of Sale?
Rate of Sale refers to the average number of units sold of a specific product over a defined period. In retail, this is most commonly expressed as "Units Per Week" (UPW) or "Units Per Store Per Week" (UPSPW). It helps retailers answer critical questions such as:
- Is this product selling fast enough to warrant a reorder?
- How long will my current stock last?
- Which store location is moving this product the fastest?
Formulas Used in This Calculator
Calculating ROS is straightforward but requires accurate data regarding units sold and the time frame analyzed. Below are the core formulas used in our calculator tool:
1. Average Weekly Rate of Sale
This is the baseline metric for total velocity.
Weekly ROS = Total Units Sold ÷ Number of Weeks
2. ROS Per Store (UPSPW)
If you operate multiple locations, looking at the aggregate total can be misleading. You need to know the average velocity per door.
ROS Per Store = Weekly ROS ÷ Number of Stores
3. Weeks Cover (Weeks of Supply)
This metric projects how long your current inventory will last based on the calculated rate of sale.
Weeks Cover = Current Inventory Level ÷ Weekly ROS
Real-World Example
Let's say you are a fashion retailer analyzing the sales of a specific denim jacket. Here is your data:
- Total Units Sold: 400 units
- Time Period: 8 weeks
- Number of Stores: 10 stores
- Current Stock: 250 units
Using the formulas above:
- Weekly ROS: 400 ÷ 8 = 50 units per week (total).
- ROS Per Store: 50 ÷ 10 = 5 units per store per week.
- Weeks Cover: 250 ÷ 50 = 5 weeks of inventory remaining.
This tells you that while the product is selling steadily, you only have enough stock for a little over a month, indicating an urgent need to reorder if the lead time is long.
Why is ROS Different from Sell-Through Rate?
It is common to confuse Rate of Sale with Sell-Through Rate, but they measure different things:
- Rate of Sale (ROS): Measures velocity (speed). It answers "How many units do we sell per week?"
- Sell-Through Rate (STR): Measures percentage of inventory depleted. It answers "What fraction of the stock we bought have we sold?"
A product can have a high sell-through (90% sold) but a low rate of sale if it took a very long time to sell that 90%. Conversely, a product can have a high ROS but low sell-through if you bought a massive amount of inventory.
Tips for Optimizing Rate of Sale
If your calculation shows a lower ROS than expected, consider these strategies:
- Merchandising: Ensure the product is displayed in high-traffic zones or featured in window displays.
- Pricing Strategy: Analyze if the price point is competitive. Promotional offers can artificially spike ROS to clear slow-moving stock.
- Inventory Allocation: Move stock from low-ROS stores to high-ROS stores to maximize sales opportunities without purchasing new inventory.