let refinanceSteps = “”; const currencySymbol = “$”, fixedCurrency = “USD”; function calculateRefinance(){ refinanceSteps=””; const loanAmount = parseFloat(document.getElementById(“currentLoanAmount”).value); const currentRate = parseFloat(document.getElementById(“currentInterestRate”).value) / 100; const currentTerm = parseFloat(document.getElementById(“currentLoanTerm”).value) * 12; const refinanceRate = parseFloat(document.getElementById(“refinanceInterestRate”).value) / 100; const refinanceTerm = parseFloat(document.getElementById(“refinanceLoanTerm”).value) * 12; if (isNaN(loanAmount) || isNaN(currentRate) || isNaN(currentTerm) || isNaN(refinanceRate) || isNaN(refinanceTerm)) { alert(“Please enter valid positive values for all fields.”); return; } const currentMonthlyPayment = loanAmount * (currentRate / 12) * Math.pow(1 + currentRate / 12, currentTerm) / (Math.pow(1 + currentRate / 12, currentTerm) – 1); const refinanceMonthlyPayment = loanAmount * (refinanceRate / 12) * Math.pow(1 + refinanceRate / 12, refinanceTerm) / (Math.pow(1 + refinanceRate / 12, refinanceTerm) – 1); const totalInterestSavings = (currentMonthlyPayment * currentTerm) – (refinanceMonthlyPayment * refinanceTerm); document.getElementById(“monthlyPaymentResult”).value = formatCurrency(refinanceMonthlyPayment); document.getElementById(“totalInterestSavings”).value = formatCurrency(totalInterestSavings); refinanceSteps += `Inputs:
Current Loan Amount: ${formatCurrency(loanAmount)}
Current Interest Rate: ${(currentRate * 100).toFixed(2)}%
Current Term: ${currentTerm / 12} years
Refinance Interest Rate: ${(refinanceRate * 100).toFixed(2)}%
Refinance Term: ${refinanceTerm / 12} years

`; refinanceSteps += `Formulas:
Monthly Payment = Loan × (Rate / 12) × (1 + Rate / 12)^Term / ((1 + Rate / 12)^Term – 1)
Total Interest Savings = (Current Payment × Term) – (Refinance Payment × Term)

`; refinanceSteps += `Results:
New Monthly Payment: ${formatCurrency(refinanceMonthlyPayment)}
Total Interest Savings: ${formatCurrency(totalInterestSavings)}
`; if (document.getElementById(“calculationStepsRefinance”).style.display === “block”) { document.getElementById(“calculationStepsRefinance”).innerHTML = refinanceSteps; } } function resetRefinance(){ document.querySelectorAll(“#calculator input”).forEach(el => el.value = “”); refinanceSteps = “”; document.getElementById(“calculationStepsRefinance”).innerHTML = “

Not calculated yet.

“; } function toggleRefinanceSteps(){ const s = document.getElementById(“calculationStepsRefinance”); const a = document.getElementById(“toggleArrowRefinance”); if (s.style.display === “none” || s.style.display === “”) { s.style.display = “block”; a.style.transform = “rotate(180deg)”; s.innerHTML = refinanceSteps || “

Not calculated yet.

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