function calculateAppraisal() {
var sqFt = parseFloat(document.getElementById('totalSqFt').value);
var pricePerSqFt = parseFloat(document.getElementById('pricePerSqFt').value);
var beds = parseFloat(document.getElementById('numBedrooms').value) || 0;
var baths = parseFloat(document.getElementById('numBathrooms').value) || 0;
var age = parseFloat(document.getElementById('propertyAge').value) || 0;
var condition = parseFloat(document.getElementById('homeCondition').value);
var upgrades = parseFloat(document.getElementById('upgradeValue').value) || 0;
if (!sqFt || !pricePerSqFt) {
alert("Please enter the total square footage and local average price per square foot.");
return;
}
// Logic: Base value is sqft * local average
var baseValue = sqFt * pricePerSqFt;
// Bed/Bath premium (Approximate market standard adjustments)
var bedroomPremium = beds * 5000;
var bathroomPremium = baths * 7500;
// Depreciation: Approx 0.5% per year of age, capped at 40%
var depreciationRate = Math.min(age * 0.005, 0.40);
var depreciationAmount = baseValue * depreciationRate;
// Final Calculation
// (Base + Rooms) * Condition Factor + Upgrades – Depreciation
var estimatedValue = ((baseValue + bedroomPremium + bathroomPremium) * condition) + upgrades – depreciationAmount;
// Display results
document.getElementById('resultContainer').style.display = 'block';
document.getElementById('finalAppraisal').innerHTML = '$' + estimatedValue.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0});
document.getElementById('breakdown').innerHTML =
'Breakdown:' +
'Base Value (Size/Location): $' + baseValue.toLocaleString() + " +
'Room Adjustments: +$' + (bedroomPremium + bathroomPremium).toLocaleString() + " +
'Condition Multiplier: x' + condition + " +
'Age Depreciation: -$' + depreciationAmount.toLocaleString() + " +
'Added Upgrades: +$' + upgrades.toLocaleString();
}
How Does a Home Appraisal Work?
A home appraisal is an unbiased professional opinion of a home's value. It is used whenever a mortgage is involved in buying, refinancing, or selling a property. While our calculator provides a data-driven estimate based on standard industry adjustments, a professional appraiser will perform an on-site inspection and review local "comps" (comparable sales).
Key Factors in Determining Your Home Value
Location and Comps: The most significant factor is what similar homes in your immediate radius have sold for in the last 3-6 months.
Square Footage: The usable living space. Unfinished basements or attics are often calculated at a lower rate than finished living areas.
Condition and Age: Newer homes generally command higher prices due to less deferred maintenance. Systems like HVAC, roofing, and electrical play a major role.
Bedrooms and Bathrooms: Adding a bathroom or bedroom significantly increases the functional utility of the home, typically adding thousands to the valuation.
Upgrades: Modern kitchens, hardwood floors, and energy-efficient windows offer a high return on investment (ROI).
Calculation Example
Imagine a 2,000 square foot home in an area where the average price is $150/sq ft.
The base value starts at $300,000. If the home is 20 years old, we apply a depreciation factor. However, if the owners recently spent $20,000 on a kitchen remodel and the house is in "Excellent" condition, the multiplier shifts upward, potentially bringing the valuation to $340,000 – $360,000 depending on local bedroom/bathroom counts.
Note: This tool is for educational purposes only. For a legal or bank-verified valuation, always hire a certified licensed appraiser in your state.