THE NUMORIX GUIDE
How to use the APR Calculator
Last reviewed September 14, 2026
What this calculator does
The route calculates points as loan amount x points percent and adds other fees.
Formula and method
The route calculates points as loan amount x points percent and adds other fees. Net proceeds are loan amount minus those fees, while the monthly payment and total interest use the full loan amount at the entered note rate. Newton's method then searches for the annualized rate whose monthly present-value equation equals the net proceeds.
Variables and inputs
Enter loan amount, note interest rate, loan term in years, points percentage, and other fees in dollars. Points and note rate are percentages; term is years; fees and principal are dollars.
Worked example
For a $300,000 loan at 6.5% over 30 years with 1 point and $3,000 other fees, points cost 300,000 x 0.01 = $3,000 and total fees are $6,000. Net proceeds are $294,000, while the regular payment is about $1,896.20. Because the borrower receives less than $300,000 but repays the full schedule, the APR is above the 6.5% note rate.
How to interpret the result
APR is intended as a cost-comparison measure that incorporates the entered points and fees into an annualized borrowing rate. Compare offers with the same loan amount, term, finance-charge definitions, and timing; do not use APR alone to choose between different loan structures.
Common mistakes to avoid
Do not enter points as dollars when the field asks for a percentage. Do not subtract fees from the amortized principal in this route; the engine uses fees to reduce net proceeds. Distinguish the note rate from the solved APR.
Assumptions and limitations
The Newton solver uses the engine's fee and cash-flow model and does not implement every regulatory APR inclusion, prepaid item, irregular payment, or settlement convention. Extreme inputs can make a numerical solver sensitive, and the result is not a lender disclosure.