PALLAS / CALCULATOR
Compound Interest Calculator
Project compound growth from an initial principal, nominal annual rate, term, compounding frequency and optional contribution each compounding period. Contribution timing is explicit rather than assumed.
INPUT
Enter values
Method & formula
The nominal annual rate is divided by the number of compounding periods per year. The principal grows for every period. Repeated contributions use the future-value-of-an-annuity formula; beginning-of-period contributions receive one additional period of growth.
- Periodic rate i = nominal annual rate / compounds per year
- Principal future value = P × (1 + i)^N
- End-period contributions = C × ((1 + i)^N − 1) / i; beginning-period contributions multiply that value by (1 + i)
Example
With monthly compounding, a contribution entered here is made every month. Switching to quarterly compounding changes both the compounding interval and the contribution interval, which is stated explicitly in the result.
Sources & standards
FAQ
Is the annual rate the same as APY?
Not necessarily. The input is a nominal annual rate. Effective annual yield reflects the selected compounding frequency and is calculated separately.
How often are contributions made?
Once per selected compounding period. Monthly compounding means monthly contributions; quarterly compounding means quarterly contributions.
Does this predict investment returns?
No. It calculates a mathematical scenario from the rate you enter. Real investment returns can vary and may include fees, taxes and losses not modelled here.