Estimate your home's market value based on key property features.
—
Understanding Your Home's Estimated Market Value (Zestimate®)
A Zestimate is Zillow's estimated market value for a specific home, updated daily. It is a starting point for determining a home's value and is NOT a professional appraisal. The Zestimate is calculated using a proprietary formula that analyzes public and user-submitted data, including:
Property Characteristics: Square footage, number of bedrooms, number of bathrooms, lot size, year built, and more.
Public Records: Sales history, tax assessments, and property tax information.
User-Submitted Data: Information about renovations, upgrades, and recent sales.
Market Trends: Local housing market conditions, recent sales of comparable homes (comps), and economic indicators.
How the Zestimate Formula Works (Simplified Logic)
While the exact Zillow algorithm is complex and proprietary, a simplified model for estimating home value often considers the following factors, weighted based on their impact in a specific market:
Base Value: Often derived from a baseline price per square foot for the specific neighborhood or comparable homes.
Adjustments:
Square Footage: Larger homes generally command higher values, but the price per square foot can decrease for very large properties.
Bedrooms & Bathrooms: More bedrooms and bathrooms typically increase a home's desirability and value. Fractional bathrooms (e.g., 2.5) are common and account for half or three-quarter baths.
Year Built: Newer homes or historically significant older homes in good condition may have higher values. Age can also impact value negatively if the home requires significant updates.
Lot Size: Larger lots, especially in desirable areas, can add significant value.
Location/Neighborhood: The algorithm implicitly uses neighborhood data to establish the base value and trends.
Market Conditions: Factors like inventory levels, days on market, and recent sale prices of similar properties are crucial.
Our calculator uses a simplified model:
Estimated Value = (Square Footage * Base Price Per SqFt) + (Bedrooms * Bedroom Multiplier) + (Bathrooms * Bathroom Multiplier) + (Lot Size * Lot Multiplier) - (Current Year - Year Built) * Depreciation Factor
The exact multipliers and factors vary significantly by region and are proprietary to Zillow. This calculator uses illustrative values for demonstration purposes.
How to Use This Calculator:
Enter the details of your property into the fields above. The calculator will provide an *estimated* market value based on the simplified logic described. This is intended as an educational tool and should not replace a professional appraisal or Comparative Market Analysis (CMA) from a real estate agent.
Disclaimer: This calculator provides an illustrative estimate and is not affiliated with Zillow. It uses generalized multipliers and does not incorporate the full complexity of Zillow's proprietary Zestimate algorithm or real-time market data. For an accurate valuation, consult with a licensed real estate professional.
function calculateHouseValue() {
var sqFt = parseFloat(document.getElementById("squareFootage").value);
var beds = parseFloat(document.getElementById("bedrooms").value);
var baths = parseFloat(document.getElementById("bathrooms").value);
var year = parseFloat(document.getElementById("yearBuilt").value);
var lot = parseFloat(document.getElementById("lotSize").value);
var resultDiv = document.getElementById("result");
// Basic validation for numeric inputs
if (isNaN(sqFt) || isNaN(beds) || isNaN(baths) || isNaN(year) || isNaN(lot) ||
sqFt <= 0 || beds <= 0 || baths <= 0 || year <= 0 || lot < 0) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
resultDiv.style.backgroundColor = "#ffc107"; // Warning yellow
resultDiv.style.color = "#333";
return;
}
// — Illustrative Calculation Logic —
// These multipliers are hypothetical and simplified for demonstration.
// Real Zestimates use complex, region-specific algorithms.
var basePricePerSqFt = 150; // Hypothetical base value per square foot
var bedroomMultiplier = 10000; // Value added per bedroom
var bathroomMultiplier = 15000; // Value added per bathroom
var lotMultiplier = 50000; // Value added per acre
var depreciationFactor = 200; // Annual value depreciation
var estimatedValue = (sqFt * basePricePerSqFt) +
(beds * bedroomMultiplier) +
(baths * bathroomMultiplier) +
(lot * lotMultiplier) –
((new Date().getFullYear() – year) * depreciationFactor);
// Ensure the estimated value is not negative
if (estimatedValue < 0) {
estimatedValue = 50000; // Minimum illustrative value
}
// Format the result as currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 0,
maximumFractionDigits: 0,
});
resultDiv.innerHTML = formatter.format(estimatedValue) + " (Estimated)";
resultDiv.style.backgroundColor = "var(–success-green)"; // Success green
resultDiv.style.color = "white";
}