What it is, and what it is not
- It is a workbook file you download after buying it. It has 5 tabs, and the Payoff Plan tab holds a 120-month schedule per debt.
- It is not an online calculator, not a loan servicer tool and not a way to see your actual federal loan account.
- You type in the balance, annual rate and minimum payment of each loan, copied from your servicer statement. The workbook does not know your loans.
Where to verify your loan terms
Loan balances, rates and repayment plans come from your lender or servicer, and federal student loan rules are published by the US Department of Education at studentaid.gov. See its pages on repayment and on interest rates. Rules change, so check there before you rely on any number in a spreadsheet, including the example numbers below. Servicers also have their own rules for how an extra payment is applied (for example, to which loan or to interest first), so confirm that with your servicer. Income-driven plans do not use a fixed monthly payment; for those, enter your own estimate as the minimum.
How an extra payment changes the payoff month: exact calculator figures
Inputs, stated in full: three example debts (Debt A $5,000 at 5.5% with a $150 minimum; Debt B $12,000 at 6.8% with a $250 minimum; Debt C $2,500 at 19.9% with a $100 minimum) and an extra payment of $100.00 a month. Each month the interest is balance times annual rate divided by 12, and payments are made at month end. These are made-up debts with illustrative rates, not real loans. The figures are results of the free in-browser debt snowball calculator; example figures for the example debts shown, your results depend on your own numbers; they are not results of this spreadsheet. In the snowball and avalanche rows the extra goes to the target debt, and when a debt is paid off its whole payment moves to the next one.
| Method | Months to debt-free | Total interest | Debt A paid off in month | Debt B paid off in month | Debt C paid off in month |
|---|---|---|---|---|---|
| Minimums only (no extra) | 57 | $3,239.13 | 37 | 57 | 33 |
| Snowball, extra $100 a month | 37 | $2,273.75 | 24 | 37 | 15 |
| Avalanche, extra $100 a month | 37 | $2,249.69 | 37 | 37 | 15 |
What changed with the extra $100 a month:
- The last payoff moves from month 57 to month 37, which is 20 months sooner.
- Debt C, the loan with the highest rate, reaches zero in month 15 instead of month 33 (18 months sooner).
- Debt A reaches zero in month 24 under the snowball ordering, against month 37 with minimums only. Under the avalanche ordering it stays at month 37 because the extra goes to Debt C and then Debt B first.
- Total interest falls by $965.38 under the snowball ordering ($3,239.13 to $2,273.75) and by $989.44 under the avalanche ordering ($3,239.13 to $2,249.69).
The reason is the monthly interest formula: interest each month is balance times rate divided by 12, so every dollar that reduces a balance early also reduces the interest charged in all later months. The effect is largest on the highest-rate balance.
How the workbook handles an extra payment
On the Payoff Plan tab you type an extra monthly payment and the number (1 to 6) of the debt that receives it. The tab shows, for each debt, the payoff month and total interest without and with the extra payment, plus interest saved and months saved. The extra goes to the chosen debt only and stops when that debt is paid off; nothing is carried over to other debts, and the tab does not sort your debts. For that reason the snowball and avalanche rows above, where freed payments move to the next debt, come from the free calculator and not from a tab of the workbook. The workbook's Loan rules block is left blank on purpose so you fill it from studentaid.gov or the official source for your country.
The workbook comes in US, UK and Canada versions. Outside the US, verify terms with the official government source for your country (gov.uk for the United Kingdom, canada.ca for Canada); this site names them in text only.
What you get for USD 12
- 3 Excel-format workbooks (.xlsx): United States, United Kingdom and Canada.
- Tabs: Start, Monthly Budget, Debts (up to 6), Payoff Plan, Term Plan.
- A PDF guide that explains each tab with a worked example.
- Price: USD 12, one-time payment, sold on Gumroad. Licence: personal use. Refund on request within 14 days. The Gumroad listing carries the same terms.
How it was checked: a script verified the structure and cell references of the workbooks and compared the example schedules to a closed-form calculation. No claim is made that the files were opened in any particular spreadsheet program.
Get the student loan payoff spreadsheets, USD 12 on Gumroad
Other pages
See the debt payoff planner page, the debt snowball spreadsheet page, the budget planner template and the United States edition.