Compound Interest Calculator
Calculate savings or investment growth with compound interest. Supports daily to annual compounding, regular deposits with step-up, and optional tax on interest.
About Compound Interest Calculator
Free compound interest calculator with full support for regular contributions. Choose your compounding frequency (daily, monthly, quarterly, semi-annually, or annually), add regular deposits or withdrawals at any frequency, apply an annual step-up percentage to contributions, and account for tax on interest earned. See results as an interactive stacked growth chart showing starting amount, contributions and interest separately, plus a year-by-year and month-by-month breakdown table with CSV export. Includes Rule of 72 doubling time insight.
Frequently Asked Questions
What is compound interest?
Interest calculated on both your original principal and on interest already earned, so your money grows exponentially faster over time than with simple interest.
Can I add regular monthly deposits?
Yes — enable Regular Contributions, set your amount and frequency, and choose start or end of period timing.
Does it account for tax on interest?
Yes — enter your tax rate and the calculator deducts it from interest earned each period before it compounds, reflecting taxable accounts accurately.
Is it free?
Yes, completely free, no signup required.