Financial

Compound Interest Calculator

Calculate compound growth with deposits and a clear split between principal, contributions, and interest.

Inputs

Defaults are prefilled so the result is visible immediately.

Initial balance

Annual interest rate%

Years

Compounding

Deposit per compounding period

Results

Results update as the calculator inputs change.

Compound balance

$37,297.41

Interest earned

$14,297.41

Total deposits

$18,000.00

Compounding periods

180

Balance multiple

7.46x

Formula and Assumptions

A = P(1 + r/n)^(nt), with recurring deposits compounded at the selected interval.

Deposit timing is modeled at the end of each compounding period.

The result separates interest from deposits so growth is not overstated.

Reference Upgrade

Built from the Calculator.net model, with added context.

Live validation and instant result updates instead of a submit-only workflow.

Multiple decision metrics are shown together, not only the primary answer.

Formula notes and assumptions are visible on the page so the math is easier to audit.

Reference Model

Modeled after the input style and primary output on Calculator.net's Compound Interest Calculator.

The page keeps the math in one place and exposes the assumptions beside the result.

Default inputs: principal=5000, annualRate=5, years=15, compounding=12, deposit=100