Enter principal, annual interest rate, and term in years or months. Choose simple interest or monthly compound interest to see interest and total amount.

How to use this tool

Enter the principal amount, annual interest rate, and time period. Choose simple or compound interest and, for compound, a compounding frequency. Calculate to see total interest and the final amount.

Worked example

Example: $5,000 at 5% simple interest for 3 years earns $750 in interest for a total of $5,750. The same amount compounded monthly for 3 years grows to about $5,807; daily compounding is slightly higher.

How it works

Enter principal, annual interest rate, and term. Simple interest uses I = P × r × t. Compound interest uses standard periodic compounding at your chosen frequency (annually through daily), aligned with the compound interest calculator. Results show interest earned or charged and the total amount. Fees and taxes are not included.

Limitations

Results are estimates for educational purposes and are not financial advice. Compounding methods and fees may differ in practice. Consult a qualified financial professional for personal guidance.

Privacy and file handling

Your data stays on your device and is not uploaded.

FAQ

Frequently asked questions

What is the difference between simple and compound interest?

Simple interest is principal × rate × time. Compound interest adds interest to the balance over time; this tool compounds monthly.

Is this for loans or savings?

Either. It estimates interest on a principal over a term. For amortizing loan payments, use the Loan Calculator.

Does this include fees or taxes?

No. Results are estimates based only on principal, rate, term, and interest type.

Page last reviewed: March 1, 2026

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