Debt & Loan Calculators
Debt and loan calculators: auto loans, personal loans, and amortization with payoff projections.
Debt calculators answer a question lenders rarely put plainly: what does this actually cost, and when does it end? Every fixed-rate loan on this page amortizes the same way — interest is charged on what remains, and whatever is left of your payment reduces the balance — so the levers are always the same three: the amount, the rate, and how fast you pay. Credit cards are the exception that proves the rule, because they have no fixed term at all. The payoff date is a consequence of what you choose to pay each month.
- Author
- CentCompass
- Last Updated
- Reading Time
- 1 min read
Calculators
- Auto Loan CalculatorEstimate your monthly car payment and total interest.
- Personal Loan CalculatorEstimate your monthly personal loan payment and total cost.
- Student Loan CalculatorEstimate your monthly payment and the total cost of repayment.
- Credit Card Payoff CalculatorFind out how long your balance takes to clear and what it costs.
When to use each calculator
- Credit Card Payoff Calculator
- Use it when you carry a revolving balance. It converts your monthly payment into a payoff date and a total interest figure, and warns you when the payment is too small to ever clear the debt.
- Personal Loan Calculator
- Use it before consolidating debt or financing a large expense. It shows the fixed payment and total cost, and the content explains how origination fees push the real cost above the quoted rate.
- Student Loan Calculator
- Use it to see what a standard repayment plan costs and what extra payments save. Federal borrowers should weigh this against income-driven plans before prepaying.
- Auto Loan Calculator
- Use it before visiting a dealer, so you negotiate on the price and the rate rather than on the monthly payment a longer term can disguise.
Choosing between them
Which debt should I pay first?
Mathematically, the highest interest rate first always costs least, which usually means credit cards well before student or auto loans. Paying the smallest balance first produces quicker visible wins that some people find easier to sustain — both approaches work, but the rate-first order is the cheaper one.
Personal loan or credit card?
A personal loan carries a fixed rate, a fixed payment, and a definite end date, which makes payoff predictable. Credit cards carry variable rates that are usually far higher and minimum payments that can extend the debt for years. Consolidating only helps if you avoid rebuilding the card balance.
Should I pay extra or invest the difference?
Paying down debt earns a guaranteed return equal to its interest rate. Very few investments reliably beat a credit card APR, so high-rate debt is almost always the better target. For low-rate debt such as a subsidised student loan, the comparison gets closer.
Guides
- Debt Avalanche vs Debt SnowballTwo ways to order your debt payoff. One is mathematically cheaper, the other is psychologically easier — and the research on which actually gets finished may surprise you.
Explore more
Browse every calculator on the site, read our financial guides, or see how CentCompass is built and reviewed.
Frequently asked questions
Why does my credit card balance barely move?
Because minimum payments are set close to the interest charged. If the payment only slightly exceeds the monthly interest, almost none of it reduces the balance, and the debt stretches out for years.
What happens if my payment is smaller than the interest?
The balance grows despite you paying every month, because the unpaid interest is added back. The credit card calculator flags this case explicitly — the only fix is raising the payment above the monthly interest charge.
Do these calculators include fees?
No. Origination fees, late charges, and dealer fees are excluded, which means the true cost of some loans is higher than shown. The APR, rather than the interest rate, is the figure that captures those fees.
Is there a penalty for paying off early?
Federal student loans never carry one and it is uncommon on mainstream auto and personal loans, but it is worth confirming in your agreement before committing to an aggressive payoff plan.
Should I refinance or consolidate?
It depends on the debt. Consolidating high-rate card debt into a lower fixed rate can save real money. Refinancing federal student loans into a private loan permanently forfeits income-driven repayment and forgiveness options, which is rarely worth a modest rate cut.
Sources
- CFPB — Credit cards
- Federal Reserve — G.19 Consumer Credit
- Consumer.gov (FTC) — Credit, Loans, and Debt
How this page is produced
Editorial process. CentCompass is maintained independently, and this page is written and checked against the official publications listed above before it goes live. There is no separate editorial reviewer. This page was last checked on . See our editorial policy.
How the calculations work. Every result comes from a small, unit-tested calculation engine rather than a spreadsheet or a hardcoded table. Loans use the standard amortization formula, growth uses compound-interest math, income tax applies the federal progressive brackets, and payroll applies Social Security and Medicare rules. Our methodology sets out each one.
Where the figures come from. Tax brackets, standard deductions, FICA parameters, and contribution limits are stored once in a dated registry and read directly by the calculators — the same values appear in the text above, so the two can never drift apart. Each figure records its source, effective tax year, and review status on our data sources page.
Update policy. Regulatory figures are checked against their primary source when the IRS, SSA, or another authority publishes new values — typically each autumn for the following tax year — and again at the scheduled review date recorded for each dataset. Figures that have not been checked yet are marked as draft on the data sources page until that check is complete.
Educational purposes only — not financial, tax, or investment advice (disclaimer).