Loan Comparison Table: Compare Payments and Interest

A loan comparison table puts the estimated monthly payment and total interest for different loan amounts, rates, or terms side by side. This calculator estimates the fixed monthly payment and total interest for one loan; use it for each option, then record the results in a table to compare them consistently.

Formula

The monthly payment is the level-payment loan formula: PMT = P × r ÷ [1 − (1 + r)⁻ⁿ]. Total interest is I = PMT × n − P. Here, P is the amount borrowed in dollars, r is the monthly interest rate as a decimal (APR ÷ 1,200), and n is the number of monthly payments (years × 12). APR is entered as a percentage per year.

The calculator rounds the displayed monthly payment to cents. It then uses that rounded payment to estimate total interest, so the result can differ slightly from a calculation that retains extra decimals throughout. The formula assumes regular, equal payments and a fixed rate.

Worked Example

Using the defaults—$20,000 borrowed, 8% APR, and a five-year term:

1. Convert the APR to a monthly decimal rate: 8 ÷ 1,200 = 0.0066667.
2. Convert the term to payments: 5 × 12 = 60 months.
3. Substitute into the payment formula: $20,000 × 0.0066667 ÷ [1 − (1 + 0.0066667)⁻⁶⁰] = $405.53 per month, rounded to cents.
4. Estimate total interest using the rounded payment: $405.53 × 60 − $20,000 = $4,331.80.

Assumptions

• The interest rate is fixed for the entire term.
• Payments are equal, made monthly, and paid at the end of each period.
• Interest is modelled monthly at APR divided by 12.
• Fees, taxes, insurance, escrow, and any charges not entered as part of the principal are not included.

How to Build a Useful Loan Comparison Table

Run the calculator separately for each loan scenario and copy the inputs and outputs into a table. Keep the assumptions consistent: compare the same amount borrowed and the same kinds of costs, unless the purpose is specifically to see how changing the amount affects a payment.

A practical table might include these columns:

• Loan amount
• APR supplied for the scenario
• Term in months or years
• Estimated monthly payment
• Estimated total of payments
• Estimated total interest
• Fees or other costs, entered separately when known

For example, compare a five-year and a seven-year term only after entering the same principal and APR in both runs. A longer term generally spreads repayment across more months, which can lower the formula’s monthly payment while increasing the total interest when the rate and principal are held constant. This is a mathematical comparison, not a statement about a particular loan offer.

How to Interpret the Results

The monthly payment shows the scheduled principal-and-interest amount under the formula’s assumptions. Total interest estimates the interest paid over the full term if every payment is made as scheduled. It is not the total amount paid: add the principal to the interest to estimate total payments. In the worked example, total payments are $24,331.80, consisting of $20,000 principal and $4,331.80 estimated interest.

A loan comparison table is most informative when it separates payment size from overall cost. A lower monthly payment alone does not establish that one scenario costs less; the term, rate, fees, and other included charges matter. If a lender provides a payment or total-cost disclosure, compare its definitions and included items with the calculator’s assumptions rather than treating unlike figures as directly interchangeable.

Common Comparison Problems and Limits

APR and interest rate are related but should not be assumed to represent identical figures in every offer. The APR supplied by a lender may reflect costs or calculation conventions that this basic formula does not model. Enter the relevant rate exactly as stated in the loan information, and do not add fees to the APR or principal unless the lender’s figures support that treatment. Obtain the actual rate, fees, and payment details from the lender.

• Comparing different loan amounts: a larger principal usually produces a larger payment, so isolate rate or term differences by holding the amount constant.
• Leaving out fees: this calculator does not estimate fees or other charges unless they are included in the amount borrowed. List them separately when comparing documented offers.
• Rounding: monthly payments are rounded to cents. Real schedules may include a small adjustment to the final payment.
• Variable rates or irregular payments: a fixed-rate, level-payment formula does not represent a changing rate, skipped payment, or extra payment schedule.
• Using the result as an approval or budget decision: the calculation does not determine eligibility, affordability, or a lender’s terms.

For a fuller comparison, use the lender’s written payment schedule and itemized costs alongside these estimates. A table is a way to organize figures, not a substitute for checking that each figure refers to the same loan structure and time period.

Frequently Asked Questions

What should a loan comparison table include?
At minimum, list principal, APR, term, estimated monthly payment, and estimated total interest. Record fees separately if known, and label whether totals include them.

Does a lower monthly payment mean a loan costs less?
Not necessarily. A longer repayment term can reduce the scheduled monthly payment but increase total interest. Compare the term and total costs as well as the payment.

Is total interest the same as total repayment?
No. Total interest is the estimated borrowing cost under the formula. Total repayment includes both principal and interest, before any excluded fees or charges.

Can I compare loans with different terms?
Yes. Enter each term separately and keep other inputs consistent when you want to see the effect of term length. Note that the calculator assumes equal monthly payments and a fixed rate.

Why might a lender’s payment differ from this estimate?
The lender’s calculation may include fees, a different payment schedule, a different rate convention, or other loan terms. Check the lender’s disclosure for the exact figures and what they include.

This result is an estimate; the lender’s disclosure gives the exact figures.

Related

• Cheap Personal Loan Comparison Calculator
• Car Loan Comparison Calculator: Compare Monthly Payments
• Car Loan Comparison Calculator: Compare Payments

in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
out pmt | Monthly payment | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2