Loan comparison calculator

Decide what the comparison should isolate

Use the same amount and term to compare interest rates. Keep the amount and rate fixed to compare term lengths. Changing all three at once can hide why the payment or cost differs.

Each scenario uses constant monthly payments with interest on the declining balance. The schedule rounds monthly interest and payments, and adjusts the final payment. It excludes upfront fees, insurance, rate resets, taxes and penalties.

The same loan at 5% and 7%

Consider 10,000.00 borrowed for 36 months, with no fees. At 5%, the regular payment is 299.71. At 7%, it is 308.77, a regular-payment difference of 9.06 per month.

Using the stated cent-rounding convention and an adjusted final payment, total interest is approximately 789.54 at 5% and 1,115.76 at 7%. The interest difference is 326.22. This illustrates a controlled rate comparison, not a live lender offer.

A rate comparison is not a regulated APR comparison

A fee can reverse the ranking of two otherwise similar offers, especially if you repay early. Compare verified fees, the time you expect to keep the loan and any repayment restrictions. A payment formula does not derive a legally compliant APR.

CFPB: mortgage interest rate and APR explains the distinction for U.S. mortgages. Microsoft: constant-payment loan calculations specifies that the constant-payment calculation itself excludes taxes and fees.

A lower payment does not by itself establish a cheaper loan. Read the interest, fees and APR comparison; if you plan to repay faster, use the overpayment tool with the same starting terms before comparing modeled totals.

Keep a copy of the actual offers

Write down the amount received, amount financed, rate basis, fixed period, full repayment term, required fees, payment schedule and early-repayment conditions. For a refinance, include the cost of closing the old loan as well as opening the new one. Use the calculation to organize questions, then reconcile it with each lender's disclosure.