let homeLoanSteps = “”; const currencySymbol = “$”, fixedCurrency = “NZD”; function calculateHomeLoan(){ homeLoanSteps=””; const loanAmount=parseFloat(document.getElementById(“loanAmount”).value); const interestRate=parseFloat(document.getElementById(“interestRate”).value)/100; const loanTerm=parseFloat(document.getElementById(“loanTerm”).value); const extraPayment=parseFloat(document.getElementById(“extraPayment”).value); if(isNaN(loanAmount)||isNaN(interestRate)||isNaN(loanTerm)||isNaN(extraPayment)||loanAmount<=0){ alert("Please enter valid positive values for all fields."); return; } const monthlyPayment = (loanAmount * interestRate / 12) / (1 – Math.pow(1 + interestRate / 12, -loanTerm * 12)); const newLoanTerm = Math.ceil(Math.log(1 – (extraPayment / (loanAmount * interestRate / 12))) / Math.log(1 + interestRate / 12)); const timeSaved = loanTerm * 12 – newLoanTerm; const totalInterest = loanAmount * interestRate * loanTerm – loanAmount; const interestSaved = totalInterest * (timeSaved / (loanTerm * 12)); document.getElementById("timeSaved").value = timeSaved; document.getElementById("interestSaved").value = formatCurrency(interestSaved); homeLoanSteps += `Inputs:
Loan Amount: ${formatCurrency(loanAmount)}
Interest Rate: ${(interestRate * 100).toFixed(2)}%
Loan Term: ${loanTerm} years
Extra Payment: ${formatCurrency(extraPayment)}

`; homeLoanSteps += `Formulas:
Monthly Payment = (Loan Amount × Interest Rate / 12) / (1 – (1 + Interest Rate / 12)^-Term)
Time Saved = Loan Term – New Loan Term

`; homeLoanSteps += `Results:
Time Saved: ${timeSaved} months
Interest Saved: ${formatCurrency(interestSaved)}
`; if(document.getElementById(“calculationStepsHomeLoan”).style.display===”block”){ document.getElementById(“calculationStepsHomeLoan”).innerHTML = homeLoanSteps; } } function resetHomeLoan(){ document.querySelectorAll(“#calculator input”).forEach(el=>el.value=””); homeLoanSteps=””; document.getElementById(“calculationStepsHomeLoan”).innerHTML=”

Not calculated yet.

“; } function toggleHomeLoanSteps(){ const s=document.getElementById(“calculationStepsHomeLoan”); const a=document.getElementById(“toggleArrowHomeLoan”); if(s.style.display===”none”||s.style.display===””){ s.style.display=”block”;a.style.transform=”rotate(180deg)”; s.innerHTML=homeLoanSteps||”

Not calculated yet.

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