Calculator Mortgage Extra Payments

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 = parseInt(document.getElementById(“loanTerm”).value) * 12; const extraPayments = parseFloat(document.getElementById(“extraPayments”).value); if(isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm) || isNaN(extraPayments) || loanAmount <= 0 || loanTerm 0) { balance = balance * (1 + monthlyRate) – monthlyPayment – extraPayments; if (balance < 0) { balance = 0; } months++; totalPaid += monthlyPayment + extraPayments; } const totalInterest = totalPaid – principal; document.getElementById("monthlyPayment").value = formatCurrency(monthlyPayment); document.getElementById("totalInterest").value = formatCurrency(totalInterest); document.getElementById("loanPaidOff").value = months; mortgageSteps += `Inputs:
Loan Amount: ${formatCurrency(loanAmount)}
Interest Rate: ${(interestRate * 100).toFixed(2)}%
Loan Term: ${loanTerm / 12} years
Extra Payments: ${formatCurrency(extraPayments)}

`; mortgageSteps += `Formulas:
Monthly Payment = Principal × Rate / (1 – (1 + Rate) ^ -Term)
Total Interest = Total Paid – Principal

`; mortgageSteps += `Results:
Monthly Payment: ${formatCurrency(monthlyPayment)}
Total Interest Paid: ${formatCurrency(totalInterest)}
Loan Paid Off In: ${months} months`; 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; }