This tool is built for two of the most common personal finance questions: what will my loan cost me each month, and how much will my savings grow if I leave them alone?
In Loan Payment mode it calculates your fixed monthly payment for any fixed-rate installment loan — personal loans, debt consolidation loans, student loans, or any other fixed-rate borrowing. Enter the principal, the annual interest rate, and the term in months to get your monthly payment and total interest paid.
In Future Savings mode it estimates how much a one-time lump sum will grow using the compound interest formula. This is useful for modeling returns on a high-yield savings account, a CD, or a savings bond — and for comparing what your money earns against what your debt costs you.
For loan calculations the amortization formula is used: M = P × r(1+r)^n / ((1+r)^n − 1), where P is the principal, r is the monthly interest rate, and n is the number of monthly payments. For savings, the future value formula: FV = P × (1 + r)^n.
Say you're taking out a $15,000 personal loan at 8% annual interest over 48 months. The monthly rate is 8% ÷ 12 = 0.667%. Using the amortization formula, your monthly payment would be approximately $366.19. Over 48 months, you'd repay a total of $17,577 — meaning roughly $2,577 in interest on top of the original $15,000.
Suppose you deposit $5,000 into a high-yield savings account earning 4.5% annual interest and leave it untouched for 36 months. The monthly rate is 4.5% ÷ 12 = 0.375%. After 3 years, your balance would grow to approximately $5,716 — a gain of $716 purely from compound interest, with no additional contributions.
Yes. Use the dropdown to switch between modes. "Loan Payment" calculates a fixed monthly payment to fully repay a debt over the given term. "Future Savings" calculates how much a one-time lump-sum deposit will grow with compound interest — useful for estimating returns on a CD, savings bond, or high-yield savings account.
Loan and savings terms are most precisely expressed in months since interest compounds monthly. To convert years to months, simply multiply by 12. A 3-year loan is 36 months, a 5-year loan is 60 months, and so on.
No. The loan calculation covers principal and interest only. Real-world loans may also include origination fees, prepayment penalties, or insurance requirements that affect the true cost of borrowing. Always review your lender's full loan disclosure before signing. Similarly, savings estimates assume no taxes on interest earned — actual after-tax returns will be lower depending on your tax bracket.
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus any accumulated interest — meaning your balance grows faster over time. This calculator uses compound interest for savings, which is how most modern savings accounts and investments work. For loans, amortization spreads payments evenly so that early payments are mostly interest and later payments are mostly principal.
Run each offer through the calculator and compare total amount repaid, not just monthly payment. A lower rate always reduces total cost, but a longer term adds more months of interest and can offset that savings entirely. The best loan is usually the one with the lowest total repayment you can still comfortably afford each month.
Yes — this is one of the most useful applications. Add up your existing debts and enter the combined total as the principal, then use a realistic consolidation loan rate and your preferred term. Compare the resulting monthly payment and total interest against what you're currently paying across all accounts. If the consolidation total interest is lower and the monthly payment is manageable, it's likely worth pursuing.
Federal student loans have fixed rates set by Congress each year and offer income-driven repayment options and forgiveness programs not available on private loans. Private student loans work more like personal loans — fixed or variable rates based on creditworthiness, standard amortization, no forgiveness options. This calculator models standard amortization, so it's accurate for private loans and useful for estimating standard repayment on federal loans, but won't reflect income-driven plans.
You can get a rough estimate, but our dedicated Mortgage Calculator is better suited for home loans — it uses years instead of months for the term, which is more intuitive for 15- and 30-year mortgages.
When you have both debt and savings goals, the right move is almost always a math problem, not a feelings problem. Compare your loan's interest rate against what your savings will realistically earn. If your debt costs more than your savings earn, paying down debt is the better "investment" — it gives you a guaranteed return equal to the interest rate you're eliminating.
For example: if your personal loan charges 11% APR and your high-yield savings account earns 4.5%, every extra dollar put toward the loan effectively earns you 11% — more than double what the savings account offers.
A practical decision guide based on current savings rates:
| Your Debt Rate | vs. Savings/CD Rate (~4–5%) | Recommended Approach |
|---|---|---|
| Below 4% | Debt costs less than savings earn | Save and invest — your money works harder there |
| 4–6% | Roughly a wash | Split: make minimum payments, put the rest in savings |
| 6–10% | Debt costs more | Prioritize debt payoff after building a small emergency fund |
| Above 10% | Debt costs significantly more | Pay off debt aggressively — this is your best guaranteed return |
One exception: always maintain at least a small emergency fund (1–2 months of expenses) even while aggressively paying down debt. Without it, any unexpected expense forces you back onto a credit card — often at a higher rate than the debt you were paying off.