Determining the value of a used vehicle involves analyzing several critical factors that contribute to depreciation. Unlike other assets, cars generally lose value the moment they leave the dealership. This calculator uses a multi-factor algorithm to estimate what your vehicle might be worth in today's market.
Primary Factors Influencing Vehicle Value
Age Depreciation: On average, a new car loses about 15-20% of its value in the first year and roughly 10-15% for each subsequent year.
Mileage Impact: The industry standard for "normal" use is approximately 12,000 to 15,000 miles per year. If your mileage exceeds this average, the value drops more sharply due to increased mechanical wear and tear.
Physical Condition: A vehicle's cosmetic and mechanical state is paramount. A car in "Excellent" condition can command a 20-30% premium over the same model in "Fair" condition.
Ownership History: Vehicles with a single owner are often perceived as better maintained and hold higher resale value compared to those that have changed hands multiple times.
Real-World Appraisal Example
Imagine a sedan purchased 3 years ago for $30,000. It has 36,000 miles (standard usage) and is in Good condition with only one owner.
Age Adjustment: After 3 years, the base value might drop to roughly $19,500.
Condition Adjustment: Being in "Good" condition (0.9 multiplier), the value adjusts to $17,550.
Final Appraisal: Since the mileage is within the normal range, the final estimate remains near $17,500.
Tips to Maintain Your Car's Resale Value
To ensure you get the highest possible appraisal when it's time to sell or trade in, keep detailed service records, address minor cosmetic issues like door dings promptly, and park in shaded or covered areas to protect the exterior paint and interior dashboard from UV damage.
function calculateAppraisal() {
var basePrice = parseFloat(document.getElementById("basePrice").value);
var age = parseFloat(document.getElementById("vehicleAge").value);
var mileage = parseFloat(document.getElementById("mileage").value);
var conditionMult = parseFloat(document.getElementById("condition").value);
var owners = parseFloat(document.getElementById("owners").value);
if (isNaN(basePrice) || isNaN(age) || isNaN(mileage) || isNaN(owners)) {
alert("Please fill in all fields with valid numbers.");
return;
}
// 1. Calculate Age Depreciation
// Formula: Year 1 = 20%, subsequent years = 12%
var currentValue = basePrice;
if (age > 0) {
currentValue = basePrice * 0.80; // Year 1
if (age > 1) {
for (var i = 1; i 0) {
currentValue = currentValue – (mileageDiff * 0.15);
} else {
currentValue = currentValue + (Math.abs(mileageDiff) * 0.05);
}
// 3. Apply Condition Multiplier
currentValue = currentValue * conditionMult;
// 4. Ownership Penalty
// Deduct 3% for every owner beyond the first
if (owners > 1) {
var ownerPenalty = (owners – 1) * 0.03;
currentValue = currentValue * (1 – ownerPenalty);
}
// 5. Floor the value at 10% of original price (salvage/base value)
if (currentValue < (basePrice * 0.10)) {
currentValue = basePrice * 0.10;
}
// Display Results
var resultBox = document.getElementById("resultBox");
var resultValue = document.getElementById("resultValue");
var details = document.getElementById("depreciationDetails");
resultValue.innerHTML = "$" + Math.round(currentValue).toLocaleString();
details.innerHTML = "Based on " + age + " years of depreciation and " + mileage.toLocaleString() + " miles driven.";
resultBox.style.display = "block";
}