How to Use the Loan Comparison Calculator
This loan comparison calculator helps you evaluate two loan options side-by-side with complete transparency. Enter the loan amount, interest rate, loan term (in months), and origination fees for both Loan A and Loan B. Use this to compare auto loans, personal loans, student loans, or any other installment loan.
The calculator shows a direct side-by-side comparison of monthly payment, total interest paid, total cost including fees, and the APR (Annual Percentage Rate) which incorporates fees into the effective rate. A green highlight shows which loan is cheaper for each metric, and the bottom summary tells you which loan is cheaper overall.
Loan Comparison Formula & Methodology
Monthly Payment Calculation
Both loans use the standard amortization formula: M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where M is the monthly payment, P is the loan amount, r is the monthly interest rate (APR ÷ 12), and n is the total number of months.
APR Calculation
APR includes both the interest rate and fees to show the true cost of borrowing. APR ≈ ((Total Cost + Fees − Loan Amount) ÷ Loan Amount) ÷ (Term in Years) × 100. APR is always equal to or higher than the interest rate, and comparing APRs is the fairest way to evaluate loans with different fee structures.
Total Cost
Total Cost = (Monthly Payment × Term in Months) + Fees. This is the true dollar figure you'll pay over the life of the loan. A loan with a lower interest rate but higher fees may have a higher total cost — our calculator shows you the real bottom line.
| Loan Amount | Rate | Term | Monthly Payment | Total Interest | APR |
|---|---|---|---|---|---|
| $10,000 | 6.5% | 60 mo | $195.66 | $1739.69 | 6.5% |
| $20,000 | 6.5% | 60 mo | $391.32 | $3479.38 | 6.5% |
| $30,000 | 6.5% | 60 mo | $586.98 | $5219.07 | 6.5% |
| $50,000 | 6.5% | 60 mo | $978.31 | $8698.44 | 6.5% |
Frequently Asked Questions (FAQs)
Why compare APRs instead of interest rates?
APR (Annual Percentage Rate) includes both the interest rate and any fees (origination, processing, application) to show the true annual cost of borrowing. A loan with 5.9% interest and $1,000 in fees may have a higher APR than a 6.5% loan with $0 fees. The Truth in Lending Act (TILA) requires lenders to disclose APRs so consumers can make fair comparisons. Always compare APRs, not just interest rates.
How do loan terms affect total cost?
Longer loan terms mean lower monthly payments but significantly higher total interest. Example: A $30,000 loan at 6.5% costs $587/month for 60 months (total: $35,220, interest: $5,220). The same loan for 72 months costs $502/month (total: $36,144, interest: $6,144). The 72-month term saves $85/month but costs $924 more in total interest. Always consider the total cost, not just the monthly payment.
What loans can I compare with this calculator?
This calculator works for any fixed-rate installment loan: auto loans, personal loans, student loans, debt consolidation loans, home equity loans, and small business loans. For adjustable-rate or interest-only loans, the calculations differ. For mortgage comparisons, use our dedicated mortgage refinance calculator which includes closing costs and property taxes.
How do origination fees affect loan comparison?
Origination fees (typically 1-8% of the loan amount for personal loans) directly increase your APR and total cost. A $10,000 loan at 6% with 5% origination fees ($500) has an effective APR of about 7.2%. Some lenders offer "no-fee" loans with slightly higher rates — our calculator helps you compare both scenarios to find the best deal.
Should I choose a shorter or longer loan term?
Shorter terms (24-48 months): Higher monthly payments, lower total interest, faster debt payoff, lower interest rates typically. Longer terms (60-84 months): Lower monthly payments, higher total interest, slower equity building. General rule: choose the shortest term you can comfortably afford. For auto loans, avoid terms longer than 60 months to avoid being upside down. For personal loans, 24-48 months is ideal for most borrowers.
What is a good interest rate in 2026?
Interest rates in 2026 vary by loan type and credit score: Auto loans: 5.5-8% (new), 7-12% (used); Personal loans: 7-25% (depending on credit); Student loans (federal): 5.5-7.5%; Home equity loans: 7-9%. A "good" rate for your situation depends on your credit score (740+ gets the best rates), loan type, and current market conditions. Check multiple lenders and pre-qualify (soft credit pull) to see your actual offered rates.
Data Sources & Methodology
- APR Disclosure Requirements: Truth in Lending Act (TILA) as enforced by the Consumer Financial Protection Bureau. Lenders must disclose APR before loan closing.
- Loan Rate Benchmarks: Average consumer loan rates from Federal Reserve Economic Data (FRED). Personal loan rates averaged 10-12% in early 2026.
- Amortization Formula: Standard installment loan formula used by all major lenders. Verified for accuracy against loan amortization schedules.
Related Tools
- Mortgage Refinance Calculator — Is refinancing worth it?
- Car Loan Affordability Calculator — Can you afford that car?
- Credit Card Payoff Calculator — Compare payoff strategies.
- Home Affordability Calculator — How much house can you afford?
📖 Related Reading
For a complete guide to choosing the best loan, comparing rates, and avoiding costly mistakes, read our blog post: Loan Comparison Guide 2026.