Loan Comparison Calculator

The Loan Comparison Calculator puts up to four loan offers side by side and scores each on the numbers that actually matter: monthly payment, true APR, total interest, and total cost of borrowing. Most comparisons stop at the advertised interest rate, but the rate alone hides the real picture. By folding upfront fees and points into a true APR, this tool reveals which loan is genuinely the cheapest — which is often not the one with the lowest rate or the smallest payment.

Why Comparing Loans by Rate Alone Is Misleading

Lenders compete on the headline number — the interest rate — because it is the easiest figure to make look attractive. But two loans with the same rate can cost very different amounts once you account for origination fees, discount points, and term length. Three traps catch borrowers most often:

• Fees disguised as a low rate. A lender can advertise a below-market rate while charging discount points and origination fees that more than make up the difference.
• A small payment hiding a long term. Stretching the same loan over more years lowers the monthly payment but increases the total interest you pay.
• Different loan amounts. A larger loan at a lower rate can still cost more in absolute dollars than a smaller loan at a higher rate.

This calculator neutralizes all three by reporting the total cost and the true APR for every option on the same screen.

How the Calculator Works

For each loan, the monthly payment is found with the standard fully-amortizing loan formula:

where \(P\) is the loan amount, \(i\) is the monthly interest rate (annual rate divided by 12), and \(n\) is the number of monthly payments. From there:

The first part, \(M \times n - P\), is the total interest paid over the life of the loan. Adding the upfront fees gives the full out-of-pocket cost on top of the principal you originally received.

What Is APR and Why Does It Matter?

The APR (Annual Percentage Rate) answers the question "what does this loan really cost per year, including fees?" Where the nominal interest rate ignores upfront charges, the APR folds them in. We compute it by finding the single yearly rate at which the present value of all your payments equals the amount you actually received after fees (\(P - \text{Fees}\)). Because fees raise the effective cost of money, the APR is always at least as high as the nominal rate, and the gap grows with bigger fees and shorter terms. Comparing APRs is the fairest apples-to-apples way to rank loans.

The Three Winners

This tool highlights three separate winners because they frequently disagree:

When all three point to the same loan, the choice is easy. When they diverge, the calculator explains the trade-off so you can pick based on your own priorities.

How to Use This Calculator

1. Choose your currency from the dropdown at the top of the form.
2. Enter each loan — its amount, annual interest rate, term (in years or months), and any upfront fees or points. Give each one a name so the results are easy to read.
3. Add up to four loans with the "Add another loan" button. A minimum of two is needed to compare.
4. Click Compare Loans to see the monthly payment, total interest, true APR, and total cost for every option.
5. Review the winners and the chart to see exactly where each loan's money goes and which option fits your goal.

Tips for Comparing Loans

• Always include fees. Origination fees, discount points, and application charges belong in the comparison — leave them out and you are comparing the wrong number.
• Match the terms when you can. Comparing a 3-year loan against a 5-year loan compares cash flow, not value. Line up the terms to compare cost.
• Think about how long you will keep the loan. If you plan to pay off or refinance early, paying points for a lower rate may never pay back. A no-fee, slightly higher-rate loan can win.
• Watch for prepayment penalties. A cheap-looking loan with a prepayment penalty can cost more if you pay it off ahead of schedule.

Frequently Asked Questions

What is the best way to compare two loans?

Compare loans on their true APR and total cost, not just the advertised interest rate. The APR folds in upfront fees and points, so a loan with a lower rate but high fees can actually cost more. This calculator shows the monthly payment, total interest, total cost, and APR for each loan side by side so you can see which is genuinely cheapest.

What is the difference between interest rate and APR?

The interest rate is the cost of borrowing the principal, expressed as a yearly percentage. The APR is broader: it folds in upfront fees, points, and other charges, then expresses the total cost of the loan as a single yearly rate. Because of fees, the APR is usually higher than the nominal interest rate, and it is the fairer number for comparing offers.

Why is the loan with the lowest rate not always the cheapest?

A low interest rate can be paired with high origination fees or discount points paid upfront. Those fees raise the true cost of the loan. When you compare total cost and APR, a slightly higher-rate loan with no fees can beat a low-rate loan loaded with fees, especially if you pay it off early.

Should I pick the loan with the lowest monthly payment?

Not necessarily. A lower monthly payment usually comes from a longer term, which means you pay interest for more years and a higher total cost. The lowest monthly payment, lowest total cost, and lowest APR are often three different loans. Choose based on whether your priority is cash flow today or the cheapest loan overall.

How is the total cost of a loan calculated?

Total cost is the total interest paid over the life of the loan plus any upfront fees. Total interest equals the monthly payment multiplied by the number of payments, minus the original principal. Adding the fees gives the full out-of-pocket cost of borrowing, on top of the amount you originally received.

Does this calculator work for any type of loan?

Yes. The calculator works for any fixed-rate, fully amortizing loan, including mortgages, auto loans, personal loans, student loans, and business loans. Enter the amount, rate, term, and fees for each option and it will compare them on payment, APR, and total cost.

Additional Resources

• Annual Percentage Rate - Wikipedia
• Amortizing Loan - Wikipedia