body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 1200px;
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);
}
.calculator-title {
text-align: center;
color: #0064D2; /* eBay Blue */
margin-bottom: 25px;
font-size: 24px;
font-weight: bold;
}
.input-group {
margin-bottom: 20px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #444;
}
.input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #0064D2;
outline: none;
box-shadow: 0 0 0 2px rgba(0,100,210,0.2);
}
.calc-btn {
width: 100%;
padding: 15px;
background-color: #0064D2;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
}
.calc-btn:hover {
background-color: #0051a8;
}
#result-area {
margin-top: 25px;
padding: 20px;
background-color: #fff;
border-left: 5px solid #0064D2;
border-radius: 4px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
align-items: center;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-weight: 600;
color: #555;
}
.result-value {
font-weight: bold;
font-size: 18px;
color: #333;
}
.str-highlight {
font-size: 28px;
color: #0064D2;
}
.verdict-badge {
display: inline-block;
padding: 5px 10px;
border-radius: 15px;
font-size: 14px;
font-weight: bold;
color: white;
}
.article-content {
margin-top: 50px;
background: #fff;
padding: 20px;
}
.article-content h2 {
color: #333;
margin-top: 30px;
}
.article-content h3 {
color: #555;
}
.article-content p {
margin-bottom: 15px;
}
.article-content ul {
margin-bottom: 20px;
}
.article-content li {
margin-bottom: 8px;
}
.help-text {
font-size: 12px;
color: #777;
margin-top: 5px;
}
@media (max-width: 600px) {
.calculator-wrapper {
padding: 15px;
}
}
function calculateSTR() {
// Get input values
var activeInput = document.getElementById('activeListings').value;
var soldInput = document.getElementById('soldListings').value;
var resultArea = document.getElementById('result-area');
var strDisplay = document.getElementById('strResult');
var verdictBadge = document.getElementById('verdictBadge');
var velocityDisplay = document.getElementById('velocityResult');
var guidanceText = document.getElementById('guidanceText');
// Validation
if (activeInput === "" || soldInput === "") {
alert("Please enter both Active and Sold listing counts.");
return;
}
var active = parseFloat(activeInput);
var sold = parseFloat(soldInput);
if (isNaN(active) || isNaN(sold)) {
alert("Please enter valid numbers.");
return;
}
if (active <= 0) {
alert("Active listings must be greater than 0 to calculate a rate.");
return;
}
// Calculation: STR = (Sold / Active) * 100
var str = (sold / active) * 100;
var formattedSTR = str.toFixed(2) + "%";
// Determine Verdict and Color
var verdict = "";
var color = "";
var guidance = "";
var velocity = "";
if (str < 10) {
verdict = "Very Slow";
color = "#dc3545"; // Red
guidance = "Market is saturated. High competition, low demand. Avoid unless unique.";
velocity = "Items sit for months";
} else if (str < 40) {
verdict = "Slow / Moderate";
color = "#fd7e14"; // Orange
guidance = "Expect items to take 3-6 months to sell. Pricing must be competitive.";
velocity = "Steady but slow";
} else if (str < 100) {
verdict = "Healthy";
color = "#28a745"; // Green
guidance = "Good balance of supply and demand. Items likely sell within 1-3 months.";
velocity = "Good turnover";
} else {
verdict = "High Demand";
color = "#0064D2"; // eBay Blue
guidance = "Demand exceeds supply. Expect quick sales (often under 30 days).";
velocity = "Flying off shelves";
}
// Update DOM
resultArea.style.display = "block";
strDisplay.innerHTML = formattedSTR;
verdictBadge.innerHTML = verdict;
verdictBadge.className = "verdict-badge";
verdictBadge.style.backgroundColor = color;
velocityDisplay.innerHTML = velocity;
guidanceText.innerHTML = guidance;
}
Understanding the eBay Sell-Through Rate Calculator
Success in eCommerce, specifically on eBay, is rarely about guessing what will sell. It is about data. The eBay Sell-Through Rate (STR) is arguably the most critical metric for resellers, dropshippers, and businesses to determine if an item is worth sourcing or listing.
This calculator helps you instantly determine the health of a specific niche or product category by comparing the number of active listings (competition) against the number of sold listings (demand).
What is eBay Sell-Through Rate?
The Sell-Through Rate represents the velocity at which items in a specific category are selling. It is expressed as a percentage.
The formula used is:
(Number of Sold Listings ÷ Number of Active Listings) × 100 = STR %
Typically, this calculation is performed using data from the last 90 days (which is the standard historical data period provided by eBay's Terapeak research tool).
How to Interpret Your Results
Once you input your numbers into the calculator above, you will get a percentage. Here is how to interpret that data for sourcing decisions:
- Under 10% (Low STR): This indicates a saturated market. There are far more sellers than buyers. If you list an item in this category, expect it to sit for a long time (6 months or more) unless your price is significantly lower than the competition.
- 40% – 60% (Healthy STR): This is a solid "bread and butter" zone. It indicates that for every 100 items listed, about 50 sell every 90 days. You can expect a sale within 1 to 3 months if priced correctly.
- Over 100% (High STR): This is the "unicorn" zone. A rate over 100% means there are more items selling than there are currently available. Demand exceeds supply. Items in this bracket often sell within days or hours of listing.
Real-World Example
Imagine you are at a garage sale and find a vintage "Sony Walkman". You look it up on the eBay app:
- You filter by "Active Listings" and see there are 200 currently for sale.
- You change the filter to "Sold Items" and see that 400 have sold in the last 90 days.
Plugging these numbers into the calculator:
(400 Sold ÷ 200 Active) × 100 = 200% STR
This result tells you that the item is in extremely high demand. Even if you list it at an average price, it is almost guaranteed to sell quickly because the market absorbs supply faster than sellers can list it.
Why STR Matters for Ranking
eBay's "Cassini" search engine algorithm prioritizes listings that are likely to result in a transaction. Categories with high sell-through rates signal to eBay that buyers want these items. Furthermore, if your personal store maintains a high STR (by listing desirable items), eBay is more likely to boost your listings in search results, creating a positive feedback loop for your business.
How to Find the Numbers
To use this calculator effectively, you need accurate data inputs. You can find these on eBay:
- Mobile App: Search for an item. The total results number at the top is your "Active" number. Then, go to Filter > Show More > Toggle "Sold Items". The new result number is your "Sold" number.
- Terapeak Product Research: Available in Seller Hub, this tool gives precise metrics on active and sold listings over 90 days.