Compounding frequency
Interest is converted to an equivalent monthly growth rate so recurring monthly contributions can be modelled consistently.
Calculators · Local processing
Compound Interest Calculator
Estimate investment growth with selectable compounding and monthly or yearly contributions.
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The practical guide
Separate contributions from compound growth year by year.
Compare annual, semi-annual, quarterly, monthly, or daily compounding with optional recurring deposits.
Contribution timing
Contributions are treated as end-of-period deposits. Real account timing, taxes, fees, and variable returns can change outcomes.
Lightweight visual
The SVG line shows balance growth without loading a charting library or sending calculation data elsewhere.
Privacy by architecture
Your files and tool inputs stay in your browser.
The selected files, inputs, settings, and outputs are processed in this page and are not uploaded to any server.
Questions, answered
Frequently asked questions
Are returns guaranteed?
No. The tool calculates a constant hypothetical rate and does not predict investment performance.
When are contributions added?
Monthly or yearly contributions are added at the end of each corresponding period.
Does this include taxes or fees?
No. Add those separately when comparing real accounts or products.