function calculateSaleRate() {
var startInvInput = document.getElementById('src-starting-inv');
var soldUnitsInput = document.getElementById('src-units-sold');
var resultArea = document.getElementById('src-result-area');
var errorMsg = document.getElementById('src-error-msg');
// Reset display
errorMsg.style.display = 'none';
resultArea.style.display = 'none';
var startInv = parseFloat(startInvInput.value);
var soldUnits = parseFloat(soldUnitsInput.value);
// Validation
if (isNaN(startInv) || isNaN(soldUnits)) {
errorMsg.innerText = "Please enter valid numeric values for inventory and sales.";
errorMsg.style.display = 'block';
return;
}
if (startInv <= 0) {
errorMsg.innerText = "Beginning inventory must be greater than zero to calculate a rate.";
errorMsg.style.display = 'block';
return;
}
if (soldUnits startInv) {
errorMsg.innerText = "Units sold cannot exceed beginning inventory.";
errorMsg.style.display = 'block';
return;
}
// Calculation
var saleRate = (soldUnits / startInv) * 100;
var remaining = startInv – soldUnits;
var status = "";
// Status Logic (General Retail Standards)
if (saleRate = 40 && saleRate <= 80) {
status = "Healthy / Efficient";
} else {
status = "Fast Moving (Restock Soon)";
}
// Display Results
document.getElementById('src-rate-output').innerText = saleRate.toFixed(2) + "%";
document.getElementById('src-start-output').innerText = startInv.toLocaleString();
document.getElementById('src-sold-output').innerText = soldUnits.toLocaleString();
document.getElementById('src-remain-output').innerText = remaining.toLocaleString();
document.getElementById('src-status-output').innerText = status;
// Color coding status
var statusEl = document.getElementById('src-status-output');
if(saleRate 80) statusEl.style.color = "#e6a700"; // Orange
else statusEl.style.color = "#46b450"; // Green
resultArea.style.display = 'block';
}
What is a Sale Rate (Sell-Through Rate)?
In retail and inventory management, the "Sale Rate," commonly known as the Sell-Through Rate (STR), is a critical metric that measures the efficiency of your inventory turnover. It calculates the percentage of inventory units sold during a specific time period relative to the amount of inventory received or available at the beginning of that period.
Calculating your sale rate helps retailers determine if their products are priced correctly, if marketing efforts are working, and how quickly they need to restock. A high sale rate indicates strong demand, while a low rate often suggests overstocking or pricing issues.
How to Calculate Sale Rate
The formula for calculating the sale rate is straightforward. It compares the number of units moved to the number of units you started with.
Formula: Sale Rate (%) = (Units Sold / Beginning Inventory) × 100
Calculation Example
Imagine a clothing boutique receives a shipment of 500 winter jackets at the start of the month. By the end of the month, they have sold 350 of these jackets.
Beginning Inventory: 500 units
Units Sold: 350 units
Calculation: (350 ÷ 500) = 0.70
Result: 0.70 × 100 = 70%
In this scenario, the boutique has a 70% sale rate (sell-through), which is generally considered excellent performance for a 30-day period.
Why is Sale Rate Important?
Monitoring this metric allows businesses to optimize their supply chain and cash flow.
Identify Slow Movers: Products with a sale rate below 40% usually indicate that the item is not popular or is priced too high. This signals the need for a discount or markdown strategy.
Prevent Stockouts: A rate above 80% suggests demand is outpacing supply. While good for revenue, it risks future stockouts, meaning you should reorder immediately.
Improve Cash Flow: Inventory is tied-up cash. A healthy sale rate ensures that capital is being released back into the business quickly to purchase new, fresh inventory.
What is a Good Sale Rate?
While benchmarks vary by industry, a general rule of thumb for monthly sell-through is:
Low (Under 40%): Indicates overstocking. Consider promotions or returning stock to vendors.
Healthy (40% – 80%): Good balance between sales velocity and stock levels.
High (Over 80%): Excellent demand, but high risk of running out of stock.