Interest Calculator

This tool calculates both simple and compound interest based on principal, rate, time, and compounding frequency. It outputs the interest amount and the resulting total balance, with optional per-period estimates to support quick financial planning for loans, deposits, and investments.
Conceptually, simple interest grows linearly with time, while compound interest accrues on the accumulated balance. The engine treats r as the annual nominal rate and m as the number of compounding periods per year, applying I = P × r × t for simple and A = P × (1 + r/m)^(m×t) for compound.
Core features include a mode switch between simple and compound, predefined compounding frequencies (annual, semiannual, quarterly, monthly, weekly, daily), and clear outputs: I, A, and, when relevant, per-period interest. It supports scenario comparisons by letting you change inputs and re-run quickly.
Audience includes individuals planning loans or savings, investors evaluating growth, and finance teams needing fast, repeatable calculations. Its value lies in accuracy, speed, and consistency, enabling what-if analyses without spreadsheets or manual math.