Purchasing a home in California is a significant investment, and understanding your mortgage payment is crucial.
A typical monthly mortgage payment in California, often referred to as PITI, consists of four main components:
Principal, Interest, Taxes, and Insurance.
This calculator helps you estimate these costs to better budget for your homeownership.
The Components of PITI:
Principal & Interest (P&I): This is the core loan repayment.
The Principal is the amount you borrowed, and the Interest is the cost of borrowing that money.
The calculation for P&I uses an amortization formula:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
Where:
n = Total Number of Payments (Loan Term in Years * 12)
Property Taxes: California property taxes are typically based on your home's assessed value, usually 1% of the assessed value plus any local bonds or assessments. The rate here is an estimate you provide. These taxes are usually collected by your lender and paid to the local government on your behalf.
Homeowner's Insurance: This covers potential damages to your home and liability. Lenders require it to protect their investment. The cost varies based on coverage, location, and the home's value.
Private Mortgage Insurance (PMI): If your down payment is less than 20% of the home's purchase price, lenders typically require PMI to mitigate their risk. It's usually a percentage of the loan amount, paid monthly. In California, laws may influence PMI cancellation.
How the Calculator Works:
Our California Mortgage Calculator simplifies this complex calculation.
You input the home's purchase price, your down payment, the loan term in years, the annual interest rate,
and estimated annual costs for property taxes, homeowner's insurance, and PMI.
The calculator first determines the Loan Amount:
Loan Amount = Home Purchase Price - Down Payment
It then calculates the Monthly Principal & Interest (P&I) payment using the standard mortgage formula.
Next, it estimates the monthly costs for property taxes, homeowner's insurance, and PMI by dividing the annual estimates by 12.
Finally, it sums up all these components (P&I, monthly tax, monthly insurance, monthly PMI) to provide your estimated Total Monthly PITI payment.
Why Use a Mortgage Calculator?
Budgeting: Helps you understand the full monthly cost of homeownership.
Affordability: Determine how much house you can realistically afford.
Comparison: Compare different loan scenarios (e.g., different interest rates or loan terms).
Negotiation: Understand the impact of down payment size on your monthly payments.
Remember, this calculator provides an estimate. Actual mortgage payments can vary based on lender fees, escrow impounds, specific loan products, and fluctuations in insurance and tax rates. It's always recommended to consult with a mortgage professional for precise figures and personalized advice.
function formatCurrency(amount) {
return amount.toLocaleString('en-US', { style: 'currency', currency: 'USD' });
}
function formatRate(rate) {
return rate.toLocaleString('en-US', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
}
function updateSliderValue(id, valueId) {
var slider = document.getElementById(id);
var valueDisplay = document.getElementById(valueId);
if (slider && valueDisplay) {
valueDisplay.textContent = slider.value + (id.includes("Rate") ? "%" : "");
}
}
function calculateMortgage() {
var homePrice = parseFloat(document.getElementById("homePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var loanTermYears = parseInt(document.getElementById("loanTerm").value);
var annualInterestRate = parseFloat(document.getElementById("annualInterestRate").value);
var propertyTaxRate = parseFloat(document.getElementById("propertyTaxRate").value);
var annualHomeInsurance = parseFloat(document.getElementById("homeInsurance").value);
var pmiRate = parseFloat(document.getElementById("pmiRate").value);
var loanAmountResult = document.getElementById("loanAmountResult");
var principalInterest = document.getElementById("principalInterest");
var propertyTax = document.getElementById("propertyTax");
var homeInsuranceEst = document.getElementById("homeInsuranceEst");
var pmiEst = document.getElementById("pmiEst");
var monthlyPayment = document.getElementById("monthlyPayment");
var totalEstimatedPayment = document.getElementById("totalEstimatedPayment");
// — Input Validation —
if (isNaN(homePrice) || homePrice <= 0) {
alert("Please enter a valid Home Purchase Price.");
return;
}
if (isNaN(downPayment) || downPayment homePrice) {
alert("Down Payment cannot be greater than the Home Purchase Price.");
return;
}
if (isNaN(loanTermYears) || loanTermYears <= 0) {
alert("Please enter a valid Loan Term.");
return;
}
if (isNaN(annualInterestRate) || annualInterestRate < 0) {
alert("Please enter a valid Annual Interest Rate.");
return;
}
if (isNaN(propertyTaxRate) || propertyTaxRate < 0) {
alert("Please enter a valid Annual Property Tax Rate.");
return;
}
if (isNaN(annualHomeInsurance) || annualHomeInsurance < 0) {
alert("Please enter a valid Annual Homeowner's Insurance amount.");
return;
}
if (isNaN(pmiRate) || pmiRate 0) {
calculatedPrincipalInterest = loanAmount * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
} else {
calculatedPrincipalInterest = loanAmount / numberOfPayments; // Handle 0% interest
}
var calculatedPropertyTax = (propertyTaxRate / 100) * homePrice / 12;
var calculatedHomeInsurance = annualHomeInsurance / 12;
var calculatedPMI = 0;
// PMI is typically required if Loan-to-Value (LTV) is > 80%
var ltv = (loanAmount / homePrice) * 100;
if (ltv > 80 && pmiRate > 0) {
calculatedPMI = (pmiRate / 100) * loanAmount / 12;
}
var totalMonthlyPayment = calculatedPrincipalInterest + calculatedPropertyTax + calculatedHomeInsurance + calculatedPMI;
// — Display Results —
loanAmountResult.textContent = formatCurrency(loanAmount);
principalInterest.textContent = formatCurrency(calculatedPrincipalInterest);
propertyTax.textContent = formatCurrency(calculatedPropertyTax);
homeInsuranceEst.textContent = formatCurrency(calculatedHomeInsurance);
pmiEst.textContent = formatCurrency(calculatedPMI);
monthlyPayment.textContent = formatCurrency(totalMonthlyPayment);
totalEstimatedPayment.textContent = formatCurrency(totalMonthlyPayment);
}
// Initial calculation on load
document.addEventListener('DOMContentLoaded', function() {
calculateMortgage();
});