APY Calculator

This tool computes the Annual Percentage Yield (effective annual rate), the final investment value, and the total interest earned from a principal, nominal annual interest rate, compounding frequency, and time horizon. It supports daily, monthly, quarterly, and annual compounding, and the time horizon can be entered in years, months, or days.

1. Enter Principal (e.g. 10000). 2. Enter Interest Rate as a nominal annual percentage (e.g. 5 for 5%). 3. Pick a Compounding frequency: daily (365), monthly (12), quarterly (4), or annually (1). 4. Enter Time and pick its unit: years, months, or days (months are divided by 12, days by 365). 5. Click Calculate. The result shows APY, Total value, and Total interest; Copy result copies the total value.

Let r = nominalRate / 100, n = periods per year (365, 12, 4, or 1), and t = time in years (months → value/12, days → value/365). APY = ((1 + r/n)^n − 1) × 100. Total value = P × (1 + r/n)^(n × t). Total interest = total value − P. All three outputs are rounded to 2 decimals. Note this is a single up-front deposit; no recurring contributions are modelled.