Calculate your replacement credit based on mileage usage.
Percentage of Life Used:0%
Percentage Remaining:0%
Pro-Rated Credit Value:$0.00
Your Cost for New Wheel/Tire:$0.00
*This calculation assumes a standard mileage-based pro-ration policy. Some manufacturers use tread depth measurements (32nds of an inch) for calculation.
function calculateProRata() {
// Get input values
var price = document.getElementById('currentPrice').value;
var warranty = document.getElementById('warrantyMiles').value;
var driven = document.getElementById('milesDriven').value;
// Validation
if (price === "" || warranty === "" || driven === "") {
alert("Please fill in all fields with valid numbers.");
return;
}
var priceNum = parseFloat(price);
var warrantyNum = parseFloat(warranty);
var drivenNum = parseFloat(driven);
if (isNaN(priceNum) || isNaN(warrantyNum) || isNaN(drivenNum)) {
alert("Please enter valid numeric values.");
return;
}
if (warrantyNum <= 0) {
alert("Warranty mileage must be greater than zero.");
return;
}
if (priceNum < 0 || drivenNum = warrantyNum) {
// Warranty expired by mileage
percentageUsed = 100;
percentageRemaining = 0;
creditAmount = 0;
customerPays = priceNum;
} else {
// Calculate pro-ration
percentageUsed = (drivenNum / warrantyNum) * 100;
percentageRemaining = 100 – percentageUsed;
// Credit is based on the remaining percentage of the current price
creditAmount = priceNum * (percentageRemaining / 100);
customerPays = priceNum – creditAmount;
}
// Display Results
document.getElementById('percentUsed').innerText = percentageUsed.toFixed(1) + "%";
document.getElementById('percentRemaining').innerText = percentageRemaining.toFixed(1) + "%";
document.getElementById('creditValue').innerText = "$" + creditAmount.toFixed(2);
document.getElementById('customerCost').innerText = "$" + customerPays.toFixed(2);
document.getElementById('results').style.display = "block";
}
Understanding the Pro Rata Wheel Calculator
When purchasing tires or wheels, manufacturers often provide a limited warranty based on mileage or tread life. If your tire wears out prematurely or fails due to a defect before reaching its guaranteed mileage, you are often entitled to a Pro Rata Credit. Our calculator helps you estimate the refund value or discount you should receive on a replacement tire based on how much of the original warranty you actually used.
How Pro-Rating Works for Tires and Wheels
A "Pro Rata" (proportional) warranty means you pay for the tire life you used, and the manufacturer credits you for the life you didn't get to use. The formula is straightforward:
Step 1: Determine the percentage of the warranty mileage you consumed.
Step 2: Calculate the remaining percentage (100% minus Used %).
Step 3: Multiply the current price of the replacement tire by the remaining percentage.
For example, if you bought a tire with a 60,000-mile warranty but it wore out at 30,000 miles, you have used 50% of the product. The manufacturer typically credits you 50% of the cost of a new tire.
Why Use a Pro Rata Calculator?
Before visiting a tire shop or dealership for a warranty claim, it is essential to know your numbers. Shops may sometimes calculate fees differently or add installation costs that are not covered by the pro-rata warranty. By using this tool, you can:
Verify the Credit: Ensure the shop is offering the correct discount based on your odometer reading.
Budget for Replacement: Know exactly how much "out of pocket" money you need to replace the defective wheel or tire.
Compare Warranties: See if a higher mileage warranty is worth the extra upfront cost based on your driving habits.
Important Considerations
While the calculation logic is purely mathematical, warranty terms can vary:
Road Hazard vs. Treadwear: Pro-ration usually applies to treadwear warranties. Road hazard warranties (nails, potholes) might offer full replacement certificates or different pro-ration schedules.
Tread Depth Method: Some manufacturers calculate usage based on tread depth (measured in 32nds of an inch) rather than mileage. This calculator uses the mileage method, which is most common for consumer estimation.
Incidental Costs: Pro-rata credits typically cover the cost of the tire only. Mounting, balancing, and disposal fees are usually the customer's responsibility.
Common Pro Rata Scenarios
Scenario A: Early Failure
If a tire fails at 10,000 miles on a 50,000-mile warranty, you have 80% remaining life. You should pay very little for the replacement.
Scenario B: Near End of Life
If a tire fails at 48,000 miles on a 50,000-mile warranty, the credit will be minimal (4%). In this case, the administrative effort of the claim might outweigh the small discount.