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Loan Comparison Calculator

A loan comparison calculator runs the same amortization math on two loans and compares them side by side. It shows the monthly payment, total interest, and total cost of each so you can see which one costs less.

By the Loansloth Editorial Team · Last updated 2026-09-16

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How this calculator works

Two loans can have the same amount but very different costs. This calculator runs the amortization formula on both and compares the results side by side.

For each loan: M = P * r * (1 + r)^n / ((1 + r)^n - 1), and total interest = M * n - P.

The cheaper loan is the one with the lower total cost, which is not always the one with the lower payment. A longer term can lower the payment while raising the total interest.

Enter the rates from your own offers. Rates vary by lender and credit profile.

Frequently asked questions

Why compare total interest and not just the payment?
A lower payment can come from a longer term, which adds months of interest. Total interest captures the full cost of each loan.
Should I compare loans with different terms?
Yes, but compare both the monthly payment and the total interest. A longer term usually lowers the payment and raises the total cost.
Does this comparison include fees?
No. This tool compares principal and interest only. Use the APR calculator to see how upfront fees change the yearly cost of each loan.
What does a tie mean?
A tie means both loans have the same rounded total interest. Look at the monthly payment and any fees to break the tie.

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