π Student Loan Payoff Calculator
Avalanche vs snowball across up to 3 loans: payoff order, interest saved, and your debt-free date.
Debt-Free Date
Estimates for planning only, not financial advice.
How to Use This Calculator
Enter up to three loans with their balances, APRs, and minimum payments (leave a loan blank if you only have one or two), then add the extra amount you can pay each month and pick a strategy. The calculator simulates every month of the payoff, shows the order loans get killed, the total months, total interest, how much the extra payments save versus minimums only, and your debt-free date.
Enter each loan's Balance, APR, and Minimum Payment. Skip loans you do not have by leaving the balance at 0.
Enter your Extra Payment per month, the amount above all minimums you can put toward debt.
Pick a Strategy: Avalanche attacks the highest APR first (cheapest), Snowball attacks the smallest balance first (fastest wins).
Toggle the strategy and compare. The Interest Saved line shows what your extra payments earn you versus minimums only.
Avalanche vs Snowball, Honestly
Avalanche is the math champion. Every dollar of extra payment eliminates the most expensive interest first, so total interest paid is always lowest. If two loans differ by several points of APR and the balances are large, avalanche can save thousands over snowball.
Snowball is the psychology champion. Killing a small loan completely within months gives you a visible win and frees up its minimum payment, which snowballs into the next target. Researchers who study debt payoff keep finding that people who get early wins stick with the plan longer. The right strategy is the one you will follow for years: run both here, and if the interest gap is small, follow your gut.
Federal vs Private Loans
Federal student loans come with built-in safety nets: income-driven repayment plans, deferment and forbearance during hardship, and forgiveness programs like Public Service Loan Forgiveness. Private loans have almost none of that, and their rates are usually higher because they are priced on your credit. That combination is why most payoff orders target private loans first, even under snowball logic.
Refinancing follows the same rule. Refinancing a private loan to a lower fixed rate is usually a clean win. Refinancing a federal loan into a private one permanently burns the federal protections, so do it only if you are certain you will never need them, and never while pursuing forgiveness.
Why Extra Payments Punch Above Their Weight
A minimum payment is mostly interest in the early years, especially on long standard repayment plans. Extra payments skip the line entirely: every extra dollar goes straight to principal, which permanently shrinks the balance that next month's interest is calculated on. The earlier in the loan you make extra payments, the more interest each one prevents.
Consistency matters more than size. An extra $150 every single month beats an occasional $500 windfall payment, because the monthly cadence keeps principal shrinking on schedule. If your budget is tight, even $50 extra directed at the highest-rate loan moves the needle over a 10-year plan.
Worked Example
Three loans: $18,000 at 6.8 percent ($207 minimum), $9,500 at 5.5 percent ($103 minimum), and $5,200 at 7.9 percent ($64 minimum), with $200 extra per month. Under avalanche, the $200 attacks Loan 3 first (highest APR at 7.9 percent), killing it in about 22 months, then moves to Loan 1, then Loan 2. The whole payoff takes about 82 months with roughly $6,900 of total interest.
Paying minimums only takes about 121 months with roughly $12,000 of total interest. The $200 extra saves about 39 months and roughly $5,150 in interest. Under snowball the order starts with Loan 3 as well (it is also the smallest), but then moves to Loan 2 before Loan 1, taking 83 months with about $7,270 of interest, roughly $400 more than avalanche.
Estimates for planning only, not financial advice. Make sure your minimum payments at least cover monthly interest, or balances will grow.
Frequently Asked Questions
What is the avalanche payoff method?
Avalanche means paying minimums on every loan and throwing all extra money at the highest interest rate first. It is the mathematically cheapest strategy because the highest rate is the most expensive dollar of debt you carry. Over the life of the payoff it saves the most interest, which this calculator shows in the comparison.
What is the snowball payoff method?
Snowball means paying minimums everywhere and throwing all extra money at the smallest balance first, regardless of rate. You kill whole loans fastest, which feels great and frees up minimum payments sooner. Studies suggest the quick wins help people stick with the plan, which is why it beats avalanche in practice for many borrowers despite costing a bit more interest.
Which strategy is better, avalanche or snowball?
Avalanche always wins on total interest paid. Snowball often wins on follow-through because wiping out a whole loan early keeps you motivated. Run both in this calculator: if the interest difference is small, pick the one you will actually stick with. If the difference is thousands of dollars, the math deserves a real say.
Do extra payments really make a big difference?
Yes, especially on long loans. Extra payments go entirely to principal, which shrinks the balance that future interest is charged on. Even $100 extra a month on a $30,000 loan at 6 percent can cut the payoff by about two years and save thousands in interest. The effect compounds: every extra payment makes the next one more powerful.
Should I refinance my student loans?
Refinancing private loans to a lower rate is often smart if your credit is strong. Refinancing federal loans into private ones is riskier: you permanently lose federal protections like income-driven repayment, deferment, forbearance, and loan forgiveness programs. Never refinance federal loans unless you are sure you will not need those safety nets.
What is the difference between federal and private student loans?
Federal loans come from the government with fixed rates, flexible repayment plans, and borrower protections like deferment and forgiveness programs. Private loans come from banks with rates based on your credit, and far fewer protections. That is why most advisors say: pay private loans first (usually higher rate, fewer options), then federal loans.