About this tool
What Is a Loan Comparison Calculator?
A loan comparison calculator analyzes two loan offers side-by-side, computing monthly payments, total interest, effective APR (including fees), and total cost to determine which offer saves you more money. Comparing loans requires looking beyond the advertised interest rate — closing fees, loan term, and inflation all affect the true cost.
The standard monthly payment formula is:M = P × [r(1+r)^n] // [(1+r)^n - 1]
Where P = principal, r = monthly rate, n = total months.
APR vs Interest Rate
| Metric | What It Measures |
|---|---|
| Interest Rate | Cost of borrowing the principal only |
| APR | Total cost including interest + fees + points |
A loan at 5.0% with $10,000 in fees costs more than a loan at 5.25% with $0 in fees over a short holding period. APR captures this difference. Always compare APR, not just interest rates.
When a Higher Rate Wins
A higher interest rate with lower fees can be cheaper if:
- You plan to sell/refinance within 5-7 years (not enough time to recoup high fees)
- The fee difference is large relative to the rate difference
- You need the cash that would go to closing costs for other investments
The break-even point shows how many months you need to stay in the loan for the lower-rate/higher-fee option to become cheaper.
Practical Usage Examples
Mortgage Comparison
$300K, Option A: 5.5%/30yr/$5K fees vs Option B: 5.25%/15yr/$8K fees
Option B saves ~$200K+ in total interest despite higher fees and monthly payment.Step-by-Step Instructions
Step 1: Enter Loan Amount. Input the total principal you plan to borrow (e.g., $300,000 for a mortgage, $45,000 for a car).
Step 2: Enter Option A. Provide the interest rate, loan term in years, and any upfront closing fees for the first loan offer.
Step 3: Enter Option B. Provide the competing lender's rate, term, and fees.
Step 4: Set Inflation Rate. Enter your projected annual inflation rate (default 3%) to see the real cost of each loan in today's purchasing power.
Step 5: Compare Results. The tool shows which loan costs less overall, the total savings, monthly payment difference, and inflation-adjusted analysis.
Core Benefits
Side-by-Side Comparison: Compares two complete loan offers simultaneously, including different rates, terms, AND closing fees — the only way to make an apples-to-apples decision.
Total Cost Transparency: Shows total interest paid over the full loan term, not just monthly payments. A lower monthly payment often hides a higher total cost.
APR Calculation: Estimates the effective Annual Percentage Rate including upfront fees, revealing the true borrowing cost that nominal interest rates hide.
Inflation-Adjusted Analysis: Shows the real cost of each loan after accounting for projected inflation. In high-inflation environments, long-term fixed-rate loans can be advantageous.
Frequently Asked Questions
Enter both offers into the calculator with their interest rates, terms, and closing fees. Compare the Total Cost (principal + interest + fees) — not just the monthly payment. The lower total cost is the better financial deal over the full loan term.
Not necessarily. A lower rate with high closing fees or a longer term can cost more overall. A 5.0% rate with $10,000 in fees may cost more than 5.25% with $0 fees if you sell within 5-7 years. Always compare total cost, not just the rate.
Interest rate is just the cost of borrowing principal. APR includes the interest rate PLUS closing costs, points, and other fees amortized over the loan term. APR is the only fair way to compare offers from different lenders.
15-year mortgages have higher monthly payments but save 50-60% in total interest. 30-year mortgages have lower payments but cost much more over time. Choose 15-year if you can afford the payment; 30-year if you need cash flow flexibility.
The break-even point is the number of months needed for monthly payment savings to exceed the upfront fee difference. If you pay $5,000 more in fees but save $100/month, break-even is 50 months. Stay longer = fees worth it. Leave sooner = not worth it.
Inflation reduces the real value of future payments. If you borrow at 5% and inflation is 3%, your real interest rate is approximately 2%. Long-term fixed-rate loans benefit from inflation because you repay with less valuable future dollars.
Each point (1% of loan amount) typically lowers your rate by 0.25%. Calculate the break-even: if a point costs $3,000 and saves $50/month, break-even is 60 months. Only pay points if you will keep the loan longer than break-even.
Fixed rates provide payment certainty — your payment never changes. Variable rates start lower but can increase. Choose fixed if rates are historically low or you plan to keep the loan long-term. Choose variable only if you plan to pay off quickly.
Yes. This calculator works for any loan type — mortgages, auto loans, personal loans, student loans, and business loans. Enter the principal, rate, term, and fees for any two offers to compare them.
No. All calculations run in your browser using JavaScript. Your loan amounts, rates, and financial details are never transmitted to any server or stored in any database.