Side-by-side financing math

Loan option comparison calculator

For the default $50,000 project, Option A has less total interest. Compare payment pressure separately from lifetime borrowing cost.

Terms to compare

Option A
Option B
Fixed-rate comparison
MeasureOption AOption B
Monthly payment$736.43$574.12
Total interest$11,860.12$18,894.40
Total paid$61,860.12$68,894.40

Monthly-payment difference: $162.31. Interest difference: $7,034.28.

How the comparison works

Each column uses the fixed-rate amortization formula independently: principal × monthly rate × (1 + monthly rate)months ÷ ((1 + monthly rate)months − 1). A lower payment can still carry more total interest when its term is longer.

What is excluded

The comparison excludes origination fees, closing costs, insurance, taxes, prepayment penalties, and variable-rate changes. Enter an APR that already reflects lender fees when comparing actual disclosures.