Compare High Rate (Avalanche) vs. Debt Snowball Methods
Step 1: Your Monthly Budget
How much extra money can you pay per month on top of your minimum payments?
Step 2: Enter Your Debts
Enter the balance, interest rate (APR), and minimum monthly payment for each debt.
Debt Snowball
Pay smallest balance first
$-Total Interest Paid
–Time to Debt Free
Debt Avalanche
Pay highest rate first
$-Total Interest Paid
–Time to Debt Free
function calculateDebts() {
// 1. Gather Inputs
var extraPayment = parseFloat(document.getElementById('extraPayment').value) || 0;
var debts = [];
for (var i = 1; i 0) {
if (isNaN(rate)) rate = 0;
if (isNaN(min)) min = 0;
debts.push({
id: i,
balance: bal,
rate: rate,
minPayment: min,
originalBalance: bal
});
}
}
if (debts.length === 0) {
alert("Please enter at least one debt with a balance greater than 0.");
return;
}
// 2. Run Simulations
var snowballResult = runSimulation(JSON.parse(JSON.stringify(debts)), 'snowball', extraPayment);
var avalancheResult = runSimulation(JSON.parse(JSON.stringify(debts)), 'avalanche', extraPayment);
// 3. Display Results
displayResults(snowballResult, avalancheResult);
}
function runSimulation(debtList, strategy, extraBudget) {
// Sort debts based on strategy
if (strategy === 'snowball') {
// Sort by Balance Ascending
debtList.sort(function(a, b) { return a.balance – b.balance; });
} else {
// Sort by Rate Descending (Avalanche)
debtList.sort(function(a, b) { return b.rate – a.rate; });
}
var totalInterestPaid = 0;
var months = 0;
var activeDebts = debtList.length;
// Safety brake for infinite loops (e.g., interest > payment)
var maxMonths = 1200; // 100 years
while (activeDebts > 0 && months < maxMonths) {
months++;
// Monthly rollover starts with the extra budget
var monthlyAvailable = extraBudget;
// 1. Add Minimum Payments to the "Available Pot"
// In standard snowball/avalanche, you pay minimums on all,
// and the "Extra" + "Freed up Minimums" go to the target.
// Mathematically, Total Payment = Sum(All Current Min Payments) + Extra Budget.
// Let's calculate interest and identify total payment capacity first
var monthTotalPaymentCapacity = extraBudget;
for (var i = 0; i 0) {
// Accrue Interest
var interest = debtList[i].balance * (debtList[i].rate / 100 / 12);
debtList[i].balance += interest;
totalInterestPaid += interest;
// Add this debt's min payment to the total capacity we have available to pay debts this month
monthTotalPaymentCapacity += debtList[i].minPayment;
}
}
// 2. Distribute Payments
// We iterate through the sorted list.
// Priority 1 (Index 0) gets as much as possible.
// Others get their minimums (unless capacity runs out, which shouldn't happen if inputs are valid).
var remainingCapacity = monthTotalPaymentCapacity;
// First pass: Pay minimums on non-priority debts (Index 1 to end)
// Wait, logic correction: Standard algorithm is pay minimums on ALL, then apply excess to TOP.
// Let's stick to that for clarity.
// Reset capacity logic
var excessCash = extraBudget;
// Pay Minimums on ALL debts first
for (var j = 0; j 0) {
var payment = debtList[j].minPayment;
// If balance is less than min payment, we only pay the balance
if (debtList[j].balance < payment) {
payment = debtList[j].balance;
// The unused portion of the min payment is now excess
excessCash += (debtList[j].minPayment – payment);
}
debtList[j].balance -= payment;
// If paid off during minimums
if (debtList[j].balance <= 0.001) {
debtList[j].balance = 0;
// Freed up min payment goes to excess for NEXT month,
// but strictly speaking, if we pay it off now, that money is gone for this month?
// Actually, simplified: If a debt is paid off, its min payment becomes available for the snowball immediately in subsequent months.
// For THIS month, let's treat it simply.
}
} else {
// Debt is already paid off, so its minimum payment is available as excess
excessCash += debtList[j].minPayment;
}
}
// Pay Excess to the Priority Debt (Index 0 that has balance)
for (var k = 0; k 0) {
// This is the target debt
if (debtList[k].balance >= excessCash) {
debtList[k].balance -= excessCash;
excessCash = 0;
} else {
// Pay off this debt completely with excess
excessCash -= debtList[k].balance;
debtList[k].balance = 0;
// Continue loop to apply remaining excess to next debt
}
}
}
// Check how many active debts remain
activeDebts = 0;
for (var c = 0; c 0.01) activeDebts++;
}
}
return {
interest: totalInterestPaid,
months: months,
isMaxed: months >= maxMonths
};
}
function displayResults(snowball, avalanche) {
var resultDiv = document.getElementById('results-area');
resultDiv.style.display = 'block';
// Format Currency
var fmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById('snowball-interest').innerText = fmt.format(snowball.interest);
document.getElementById('avalanche-interest').innerText = fmt.format(avalanche.interest);
document.getElementById('snowball-time').innerText = formatMonths(snowball.months);
document.getElementById('avalanche-time').innerText = formatMonths(avalanche.months);
// Recommendation Logic
var banner = document.getElementById('recommendation-banner');
var savings = snowball.interest – avalanche.interest;
var timeDiff = snowball.months – avalanche.months;
var html = "";
if (savings > 50) {
html += "Recommendation: The Avalanche Method Wins Financially.";
html += "You would save approximately " + fmt.format(savings) + " in interest by targeting high interest rates first.";
} else if (savings < -50) {
// Rare case, usually means calculation oddity or rate structures favor snowball (unlikely mathematically)
html += "Recommendation: The Results are Very Close.";
} else {
html += "Recommendation: It's a Tie Financially.";
html += "Since the interest cost is similar, choose the Debt Snowball for psychological wins.";
}
if (snowball.isMaxed || avalanche.isMaxed) {
html += "Note: One or both strategies took over 100 years. Please check if your minimum payments cover the monthly interest.";
}
banner.innerHTML = html;
// Scroll to results
resultDiv.scrollIntoView({ behavior: 'smooth' });
}
function formatMonths(totalMonths) {
if (totalMonths >= 1200) return "> 100 Years";
var years = Math.floor(totalMonths / 12);
var months = totalMonths % 12;
if (years > 0) {
return years + " yr " + months + " mo";
}
return months + " mo";
}
Snowball vs. Avalanche: Which Debt Strategy is Right for You?
When you decide to get serious about paying off debt, you will inevitably face the classic debate: Debt Snowball vs. Debt Avalanche (High Rate). While both methods have the ultimate goal of getting you to zero balance, they take different paths to get there.
The Debt Snowball Method
Popularized by financial experts who focus on behavioral psychology, the Debt Snowball method ignores interest rates. Instead, you list your debts from smallest balance to largest balance.
How it works: You pay minimums on everything, but throw every extra dollar at the smallest debt.
The Benefit: You get quick wins. Eliminating a small debt in a few months gives you a psychological boost and motivation to keep going.
The Cost: Mathematically, this is usually more expensive because you might ignore a high-interest credit card to pay off a low-interest medical bill.
The Debt Avalanche (High Rate) Method
The Debt Avalanche is the mathematically optimal strategy. You list your debts from highest interest rate to lowest interest rate.
How it works: You focus your extra budget on the debt with the highest APR, regardless of the balance size.
The Benefit: You save the most money on interest and typically get out of debt slightly faster.
The Cost: It can be discouraging. If your highest interest debt is a large student loan, it might take years to see your first account hit $0.
Frequently Asked Questions
Does the calculator include minimum payments?
Yes. The logic assumes you continue making minimum payments on all debts to avoid penalties, while the "Extra Monthly Payment" is added specifically to your target debt.
Why is the Avalanche method always cheaper?
Because you are minimizing the amount of principal that is subject to high interest rates. By attacking the highest rate, you reduce the accumulation of compound interest more effectively.
What if I have $0 extra per month?
If you have no extra money above minimums, both strategies take the exact same amount of time. The strategy only applies to where you allocate extra funds.