Loan Comparison Calculator
Loan Option A
Loan Option B
Comparison Results
Option A
Option B
What Is a Loan Comparison Calculator?
A loan comparison calculator is a tool that estimates and compares the cost of two loan options using the loan amount, annual interest rate, and loan term. It helps you see how a lower rate, shorter term, or different principal amount can change your monthly payment and total interest paid.
This loan comparison calculator shows the monthly payment, total interest, and total cost for two fixed-rate loans. It then summarizes which option has the lower monthly payment and which option saves more in total interest. The results are estimates based on a standard fully amortizing loan formula.
Borrowers often use this type of calculator before choosing between two lender quotes, loan terms, refinance options, or repayment plans. It does not decide which loan is best for you. Instead, it gives a clear side-by-side comparison so you can better understand the tradeoff between payment size and long-term interest cost.
How the Loan Comparison Calculator Formula Works
The calculator uses the standard fixed-rate amortization formula. A fully amortizing loan is paid down over time through equal monthly payments. Each payment includes interest and principal, assuming the interest rate and payment schedule stay the same.
In this formula, M is the monthly payment, P is the loan amount, r is the monthly interest rate, and n is the total number of monthly payments. The calculator finds r by dividing the annual interest rate by 100, then by 12. It finds n by multiplying the loan term in years by 12.
After calculating the monthly payment, the calculator multiplies that payment by the total number of payments to estimate total cost. It then subtracts the original loan amount from total cost to estimate total interest.
For example, with the default Option A values of $250,000, a 6.5% interest rate, and a 30-year term, the calculator estimates a monthly payment of $1,580.17. Total cost is $568,861.22, and total interest is $318,861.22.
With the default Option B values of $250,000, a 5.5% interest rate, and a 15-year term, the calculator estimates a monthly payment of $2,042.71. Total cost is $367,687.55, and total interest is $117,687.55. In this example, Option A has the lower monthly payment by $462.54, while Option B saves $201,173.67 in total interest.
If the interest rate is 0%, the calculator uses a simpler method. It divides the loan amount by the total number of monthly payments. Loan amounts and terms must be greater than zero, and interest rates cannot be negative.
How to Use the Loan Comparison Calculator: Step by Step
- Enter the Loan Amount for Loan Option A. This is the amount borrowed, not including any extra costs unless you choose to include them.
- Enter the Interest Rate (%) for Loan Option A. Use the annual rate as a percentage, such as 6.5.
- Enter the Loan Term (Years) for Loan Option A. This is the number of years used to repay the loan.
- Repeat the same three entries for Loan Option B: loan amount, interest rate, and loan term.
- Select Calculate to view the comparison results. The calculator will show monthly payment, total interest, and total cost for each option.
- Use Reset to return the calculator to its default values: $250,000 at 6.5% for 30 years and $250,000 at 5.5% for 15 years.
The results show two different parts of affordability. The monthly payment shows the estimated payment due each month. Total interest shows how much interest you may pay over the full loan term. Total cost combines the original loan amount and estimated interest.
What to Check Before You Compare Loan Options
A loan comparison is most useful when you enter loan offers in the same way. Small differences in loan amount, interest rate, or term can create large differences in long-term interest. Before you compare two options, make sure the inputs reflect the loan details you want to evaluate.
Monthly payment versus total interest
A longer loan term often lowers the monthly payment, but it can increase total interest. A shorter term may raise the monthly payment, but it can reduce the interest paid over the life of the loan. This calculator is built to show that tradeoff clearly.
Use the same type of rate
The calculator uses the interest rate you enter as an annual percentage rate for the payment formula. It does not add lender fees, points, mortgage insurance, taxes, or closing costs. If you want to compare full borrowing costs, consider those items separately.
| Calculator Field | What It Means | Used For |
|---|---|---|
| Loan Amount | The amount borrowed | Monthly payment, total cost, and total interest |
| Interest Rate (%) | The annual interest rate entered by the user | Monthly interest rate calculation |
| Loan Term (Years) | The repayment length in years | Total number of monthly payments |
| Monthly Payment | Estimated fixed monthly payment | Payment comparison |
| Total Interest | Estimated interest over the full term | Long-term cost comparison |
| Total Cost | Monthly payment multiplied by total payments | Estimated total paid over the loan term |
This tool assumes a standard fully amortizing fixed-rate loan without extra prepayments. It does not account for adjustable rates, skipped payments, early payoff, fees, taxes, escrow, insurance, or lender-specific rules. Treat the results as estimates, not as a loan approval, quote, or financial advice.
Frequently Asked Questions
What is a loan comparison calculator?
A loan comparison calculator compares two loan options using loan amount, interest rate, and loan term. It estimates each monthly payment, total interest, and total cost. This helps you see whether one option has a lower payment or saves more interest over the full repayment period.
How do I compare two loans with different terms?
To compare two loans with different terms, enter each loan amount, interest rate, and term in years. The calculator converts each term into monthly payments and estimates total cost. This makes it easier to compare a shorter loan with a higher payment against a longer loan with more interest.
Why does a shorter loan have a higher monthly payment?
A shorter loan usually has a higher monthly payment because the same principal must be repaid over fewer months. Even with a lower interest rate, fewer payments can raise the monthly amount. The tradeoff is that a shorter term may reduce total interest over the life of the loan.
What is the difference between monthly payment and total cost?
Monthly payment is the estimated amount paid each month. Total cost is the monthly payment multiplied by the total number of monthly payments. In this calculator, total cost includes the original loan amount plus estimated interest, but it does not include fees, taxes, insurance, or other charges.
Does this calculator include loan fees or closing costs?
No, this calculator does not include loan fees or closing costs. It uses only the loan amount, interest rate, and loan term entered for each option. Real loan costs may also include lender fees, discount points, taxes, insurance, escrow payments, or other charges not shown here.
How accurate is this loan comparison calculator?
This loan comparison calculator is accurate for the formula it uses, but the results are estimates. It assumes a fixed interest rate, equal monthly payments, and no extra prepayments. Actual lender payments may vary because of fees, rounding rules, escrow amounts, insurance, taxes, or loan program requirements.
Can I use this calculator for a mortgage?
Yes, you can use this calculator to compare fixed-rate mortgage payment estimates. It can show the effect of different rates and terms, such as 15 years versus 30 years. However, it does not include property taxes, homeowners insurance, mortgage insurance, HOA dues, or closing costs.