Compound Interest Calculator
Calculate how your savings or investments grow with compound interest. Supports daily, monthly, quarterly, semi-annual and annual compounding, regular deposits or withdrawals with step-up, and optional tax on interest. Includes year-by-year breakdown and visual growth chart.
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 (weekly, monthly, quarterly or annually), apply an annual step-up to your contributions, and account for tax on interest earned. See your results as an interactive stacked growth chart showing starting amount, contributions and interest separately, or a detailed year-by-year and month-by-month table you can export to CSV. Also shows your effective annual rate and a 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 faster over time than with simple interest.
What compounding frequency should I choose?
This depends on your account terms. Savings accounts often compound daily or monthly; bonds may compound semi-annually. More frequent compounding produces slightly higher returns for the same nominal rate.
Can I add regular monthly deposits?
Yes — enable Regular Contributions, set your amount and frequency (weekly, monthly, quarterly or annually), and choose whether the deposit happens at the start or end of each period.
What does "increase contributions each year" do?
It automatically increases your recurring contribution by a fixed percentage every 12 months, useful for modeling contributions that grow with your salary.
Does it account for tax on interest?
Yes — enter your tax rate on interest and the calculator deducts it from interest earned each period before it compounds, which more realistically reflects taxable accounts.
Is it free?
Yes — completely free, no signup required.