Compound Interest Calculator
Model principal growth with selectable compounding and contribution timing.
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Compound Interest Calculator formula
Each contribution period accrues the equivalent rate derived from the selected annual compounding schedule.
Worked example
10,000 at 5% compounded monthly for one year grows to about 10,511.62 without contributions.
How to use this calculator
- Enter principal, rate and duration.
- Choose compounding and optional contributions.
- Calculate the estimated balance.
Important assumptions and limitations
This is an estimate. Rates are assumed fixed; taxes, fees and market changes are excluded.
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Frequently asked questions
How are contributions handled?
They are applied monthly or yearly at the beginning or end of each contribution period.
Does daily mean 365 compounds?
Yes. Daily compounding uses 365 periods per year.