let mortgageSteps = “”; const currencySymbol = “$”, fixedCurrency = “USD”; function calculateMortgage(){ mortgageSteps=””; const loanAmount = parseFloat(document.getElementById(“loanAmount”).value); const interestRate = parseFloat(document.getElementById(“interestRate”).value) / 100 / 12; const loanTerm = parseFloat(document.getElementById(“loanTerm”).value) * 12; const balloonPayment = parseFloat(document.getElementById(“balloonPayment”).value); if (isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm) || isNaN(balloonPayment) || loanAmount <= 0 || interestRate <= 0 || loanTerm <= 0 || balloonPayment <= 0) { alert("Please enter valid positive values for all fields."); return; } const numerator = interestRate * loanAmount; const denominator = 1 – Math.pow(1 + interestRate, -loanTerm); const monthlyPayment = (numerator / denominator) + (balloonPayment / loanTerm); document.getElementById("monthlyPayment").value = formatCurrency(monthlyPayment); mortgageSteps += `Inputs:
Loan Amount: ${formatCurrency(loanAmount)}
Interest Rate: ${(interestRate * 100).toFixed(2)}%
Loan Term: ${loanTerm / 12} Years
Balloon Payment: ${formatCurrency(balloonPayment)}

`; mortgageSteps += `Formula:
Monthly Payment = (Loan Amount × Interest Rate / (1 – (1 + Interest Rate) ^ -Loan Term)) + (Balloon Payment / Loan Term)

`; mortgageSteps += `Result:
Estimated Monthly Payment: ${formatCurrency(monthlyPayment)}
`; if (document.getElementById(“calculationStepsMortgage”).style.display === “block”) { document.getElementById(“calculationStepsMortgage”).innerHTML = mortgageSteps; } } function resetMortgage(){ document.querySelectorAll(“#calculator input”).forEach(el => el.value = “”); mortgageSteps = “”; document.getElementById(“calculationStepsMortgage”).innerHTML = “

Not calculated yet.

“; } function toggleMortgageSteps(){ const s = document.getElementById(“calculationStepsMortgage”); const a = document.getElementById(“toggleArrowMortgage”); if (s.style.display === “none” || s.style.display === “”) { s.style.display = “block”; a.style.transform = “rotate(180deg)”; s.innerHTML = mortgageSteps || “

Not calculated yet.

“; } else { s.style.display = “none”; a.style.transform = “rotate(0deg)”; } } function formatCurrency(n) { return currencySymbol + n.toFixed(2) + ” ” + fixedCurrency; }