Should you sign a lease or a mortgage? Calculate your net financial position.
Property & Loan Details
Rental Comparison
Expenses & Future Outlook
Buying Net Equity
Renting Net Equity
Difference
Understanding the Rent vs. Buy Analysis
Deciding between purchasing a home and renting is one of the most significant financial decisions you will make. While homeownership is often touted as the key to wealth building, strictly looking at the mathematics reveals that renting can sometimes be the superior financial choice, depending on market conditions, interest rates, and how long you plan to stay.
How This Calculator Works
This calculator performs a Net Wealth Comparison at the end of your specified holding period. It compares two scenarios:
The Buy Scenario: It calculates the future value of the home, subtracts the remaining mortgage balance, and subtracts the transaction costs of selling (agent fees, etc.). It also accounts for the "opportunity cost" of your down payment not being invested in the stock market.
The Rent Scenario: It assumes you take the cash you would have used for a down payment and closing costs and invest it instead. It also assumes you invest any monthly savings if renting is cheaper than buying. If buying is cheaper monthly, it subtracts that difference from your investment pot.
Key Factors Influencing the Verdict
1. The Time Horizon: Transaction costs in real estate are high (often 6-10% to sell). It typically takes 5 to 7 years for home appreciation to offset these initial costs. If you plan to move in 3 years, renting is almost mathematically guaranteed to be cheaper.
2. Opportunity Cost: A large down payment tied up in a house isn't earning stock market returns. If the housing market is flat (low appreciation) but the stock market is booming, renters who diligently invest their savings often come out ahead.
3. Unrecoverable Costs: Renters pay rent. That is their unrecoverable cost.
Buyers pay mortgage interest, property taxes, HOA fees, homeowners insurance, and maintenance. These are also unrecoverable costs. Buying only makes sense when the unrecoverable costs of buying are significantly lower than rent, or when appreciation is high enough to subsidize them.
What is the "Breakeven Horizon"?
The breakeven horizon is the number of years it takes for the cost of buying to equal the cost of renting. Before this point, renting is cheaper. After this point, buying is cheaper. In high-interest rate environments, this timeline extends significantly, meaning you must stay in the home longer to make the purchase worthwhile.
function calculateRentVsBuy() {
// 1. Get Inputs
var homePrice = parseFloat(document.getElementById('rvb_homePrice').value);
var downPaymentPercent = parseFloat(document.getElementById('rvb_downPayment').value);
var interestRate = parseFloat(document.getElementById('rvb_interestRate').value);
var loanTerm = parseFloat(document.getElementById('rvb_loanTerm').value);
var monthlyRent = parseFloat(document.getElementById('rvb_monthlyRent').value);
var rentInflation = parseFloat(document.getElementById('rvb_rentInflation').value);
var years = parseFloat(document.getElementById('rvb_holdingPeriod').value);
var appreciation = parseFloat(document.getElementById('rvb_homeAppreciation').value);
var investReturn = parseFloat(document.getElementById('rvb_investmentReturn').value);
var maintCostRate = parseFloat(document.getElementById('rvb_maintCost').value);
var buyingClosingPct = parseFloat(document.getElementById('rvb_buyingCost').value);
var sellingClosingPct = parseFloat(document.getElementById('rvb_sellingCost').value);
// Validation
if (isNaN(homePrice) || isNaN(monthlyRent) || isNaN(years)) {
alert("Please check your inputs. All fields are required.");
return;
}
// — BUY SCENARIO CALCULATION —
// Initial Costs
var downPaymentAmount = homePrice * (downPaymentPercent / 100);
var loanAmount = homePrice – downPaymentAmount;
var buyingClosingAmount = homePrice * (buyingClosingPct / 100);
var initialCashOutlay = downPaymentAmount + buyingClosingAmount;
// Mortgage Details
var monthlyRate = (interestRate / 100) / 12;
var totalMonths = loanTerm * 12;
var monthlyMortgagePayment = 0;
if (interestRate === 0) {
monthlyMortgagePayment = loanAmount / totalMonths;
} else {
monthlyMortgagePayment = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalMonths)) / (Math.pow(1 + monthlyRate, totalMonths) – 1);
}
var remainingLoanBalance = loanAmount;
var currentHomeValue = homePrice;
// Total costs tracked for reference, but mainly tracking Net Worth
// Buy Net Worth = (Home Value – Mortgage – Selling Costs) + (Invested Savings from monthly difference)
// — RENT SCENARIO CALCULATION —
// Rent Net Worth = (Initial Cash Outlay Invested) + (Invested Monthly Differences)
// We simulate month by month to handle changing rent and compounding investment
var renterPortfolio = initialCashOutlay; // Renter invests the downpayment + closing costs
var buyerPortfolio = 0; // Buyer invests if Mortgage < Rent
var currentRent = monthlyRent;
var annualRentInflation = rentInflation / 100;
var annualAppreciation = appreciation / 100;
var annualInvestReturn = investReturn / 100;
var monthlyInvestReturn = Math.pow(1 + annualInvestReturn, 1/12) – 1;
// Loop through holding period
for (var m = 1; m <= years * 12; m++) {
// 1. BUYER COSTS FOR THIS MONTH
// Interest & Principal
var interestPayment = remainingLoanBalance * monthlyRate;
var principalPayment = monthlyMortgagePayment – interestPayment;
if (remainingLoanBalance 0) {
// Rent is more expensive. Buyer saves the difference and invests it.
buyerPortfolio += difference;
} else {
// Buy is more expensive. Renter saves the difference (cost avoided) and invests it.
// difference is negative here, so we subtract it (adding the positive magnitude)
renterPortfolio += Math.abs(difference);
}
// 4. UPDATES FOR NEXT MONTH
remainingLoanBalance -= principalPayment;
// Update annual figures at end of year
if (m % 12 === 0) {
currentRent *= (1 + annualRentInflation);
currentHomeValue *= (1 + annualAppreciation);
}
}
// — FINAL RESULTS —
// Buyer Final Equity
var sellingCosts = currentHomeValue * (sellingClosingPct / 100);
var homeEquity = currentHomeValue – remainingLoanBalance – sellingCosts;
var totalBuyerNetWorth = homeEquity + buyerPortfolio;
// Renter Final Equity
var totalRenterNetWorth = renterPortfolio;
// Comparison
var finalDiff = totalBuyerNetWorth – totalRenterNetWorth;
// Formatting function
var fmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', maximumFractionDigits: 0 });
// Update UI
var resultDiv = document.getElementById('rvb_result');
var verdictText = document.getElementById('rvb_verdict_text');
var summaryDesc = document.getElementById('rvb_summary_desc');
resultDiv.style.display = 'block';
document.getElementById('rvb_buy_equity').innerText = fmt.format(totalBuyerNetWorth);
document.getElementById('rvb_rent_equity').innerText = fmt.format(totalRenterNetWorth);
document.getElementById('rvb_diff_val').innerText = fmt.format(Math.abs(finalDiff));
if (finalDiff > 0) {
verdictText.innerHTML = "Buying is Better";
verdictText.style.color = "#2f855a"; // Green
summaryDesc.innerHTML = "After " + years + " years, buying leaves you wealthier by approximately " + fmt.format(finalDiff) + " compared to renting and investing the difference.";
} else {
verdictText.innerHTML = "Renting is Better";
verdictText.style.color = "#c53030"; // Red-ish
summaryDesc.innerHTML = "After " + years + " years, renting and investing your savings leaves you wealthier by approximately " + fmt.format(Math.abs(finalDiff)) + " compared to buying.";
}
// Scroll to result
resultDiv.scrollIntoView({behavior: "smooth"});
}