function calculate() { const price = Number(document.getElementById("price").value) || 0; const cost = Number(document.getElementById("cost").value) || 0; const shipping = Number(document.getElementById("shipping").value) || 0; const feeRate = (Number(document.getElementById("feeRate").value) || 0) / 100;
const fee = Math.round(price * feeRate); const net = price - shipping - fee; const profit = net - cost; const profitRate = price > 0 ? (profit / price) * 100 : 0;
let breakEven = 0; if (1 - feeRate > 0) { breakEven = Math.ceil((cost + shipping) / (1 - feeRate)); }
document.getElementById("fee").textContent = fee.toLocaleString(); document.getElementById("net").textContent = net.toLocaleString(); document.getElementById("profit").textContent = profit.toLocaleString(); document.getElementById("profitRate").textContent = profitRate.toFixed(1); document.getElementById("breakEven").textContent = breakEven.toLocaleString(); }
calculate();