Calculating your profit before sourcing a product is the most critical step for any Amazon FBA seller. Many sellers fail because they overlook "hidden" costs like Amazon's referral fees, storage costs, and PPC (Pay-Per-Click) advertising expenses.
Key Components of the FBA Calculator
Referral Fee: Amazon's commission for selling on their platform. This is usually 15% for most categories, but can range from 8% to 45%.
Fulfillment Fee: The cost Amazon charges to pick, pack, and ship your product. This depends on the weight and dimensions of your item.
COGS (Cost of Goods Sold): The raw cost of manufacturing your product and shipping it from the factory to Amazon's warehouse.
PPC Spend: Your marketing cost per unit. To find this, divide your total monthly ad spend by the total number of units sold.
Real-World Example Calculation
Imagine you are selling a yoga mat for $35.00:
Product Cost
$10.00
Referral Fee (15%)
$5.25
Fulfillment Fee
$6.50
PPC Ad Spend
$3.00
Net Profit
$10.25
In this scenario, your Profit Margin is 29.3% and your ROI is 102.5%. A healthy FBA business typically aims for a profit margin above 25%.
function calculateFBAProfit() {
var sellingPrice = parseFloat(document.getElementById('fba_selling_price').value);
var productCost = parseFloat(document.getElementById('fba_product_cost').value);
var shippingCost = parseFloat(document.getElementById('fba_shipping_cost').value);
var referralRate = parseFloat(document.getElementById('fba_referral_rate').value);
var fulfillmentFee = parseFloat(document.getElementById('fba_fulfillment_fee').value);
var storageFee = parseFloat(document.getElementById('fba_storage_fee').value);
var ppcSpend = parseFloat(document.getElementById('fba_ppc_spend').value);
// Default 0 for optional or empty fields
if (isNaN(sellingPrice)) sellingPrice = 0;
if (isNaN(productCost)) productCost = 0;
if (isNaN(shippingCost)) shippingCost = 0;
if (isNaN(referralRate)) referralRate = 0;
if (isNaN(fulfillmentFee)) fulfillmentFee = 0;
if (isNaN(storageFee)) storageFee = 0;
if (isNaN(ppcSpend)) ppcSpend = 0;
// Logic
var referralFee = sellingPrice * (referralRate / 100);
var totalAmazonFees = referralFee + fulfillmentFee + storageFee;
var totalUnitCost = productCost + shippingCost + totalAmazonFees + ppcSpend;
var netProfit = sellingPrice – totalUnitCost;
var profitMargin = 0;
if (sellingPrice > 0) {
profitMargin = (netProfit / sellingPrice) * 100;
}
var roi = 0;
var initialInvestment = productCost + shippingCost;
if (initialInvestment > 0) {
roi = (netProfit / initialInvestment) * 100;
}
// Display Results
document.getElementById('res_total_fees').innerHTML = '$' + totalAmazonFees.toFixed(2);
document.getElementById('res_total_cost').innerHTML = '$' + totalUnitCost.toFixed(2);
document.getElementById('res_net_profit').innerHTML = '$' + netProfit.toFixed(2);
document.getElementById('res_margin').innerHTML = profitMargin.toFixed(2) + '%';
document.getElementById('res_roi').innerHTML = roi.toFixed(2) + '%';
// Highlight profit/loss
if (netProfit < 0) {
document.getElementById('res_net_profit').style.color = '#cc0000';
} else {
document.getElementById('res_net_profit').style.color = '#008a00';
}
document.getElementById('fba_results').style.display = 'block';
}