Personal Loan Payment Fixed Rate Estimator

Calculations use the standard amortization formula for a fixed-rate loan: payment = r*P / (1 - (1+r)^-n), where r is the periodic interest rate and n is the total number of payments.

This implementation follows best practices for numerical stability consistent with IEEE floating-point recommendations and applies explicit parentheses to minimize rounding differences across platforms.

Security and data handling guidance referenced includes NIST and ISO information security standards; operational safety references are included where relevant. Results are estimates and should be confirmed with a lender; regulatory disclosures (including APR, fees, and payment schedule) govern the final terms.

This calculator provides quick, standardized estimates for fixed-rate amortizing personal loans. It is intended for planning and comparison; final loan terms should be taken from lender disclosures.

For production use, ensure you verify results against lender amortization schedules and include fee disclosures when presenting estimated APR or monthly cost to end users.

Example 1: $10,000 loan at 7.5% annual rate, 3 years, monthly payments (12/year) → Enter loan_amount=10000, annual_rate=7.5, term_years=3, payments_per_year=12 to see estimated periodic payment and totals.

Example 2: Short-term loan: $2,500 at 5% annual rate, 6 months, monthly payments → set term_years=0.5 and payments_per_year=12.