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

`; mortgageSteps += `Formula:
Monthly Repayment = Loan Amount × Monthly Rate ÷ (1 – (1 + Monthly Rate) ^ -Number of Payments)

`; mortgageSteps += `Result:
Estimated Monthly Repayment: ${formatCurrency(monthlyRepayment)}
`; mortgageSteps += `Tip: The longer the loan term, the lower the monthly repayment, but the higher the total interest paid over the loan period.`; 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;}