Compound Interest Calculator

See how your money grows with compound interest and regular contributions

How Compound Interest Works

Compound interest calculates interest on both the initial principal and the accumulated interest from previous periods. Combined with regular monthly contributions, it demonstrates the powerful effect of compounding over time. The calculator supports different compounding frequencies to show how more frequent compounding accelerates growth.

Formula

A = P(1 + r/n)^(nt) + PMT * [((1 + r/n)^(nt) - 1) / (r/n)]

Key Features

  • Calculate compound interest on initial principal
  • Include regular monthly contributions
  • Choose compounding frequency: daily, monthly, quarterly, or annually
  • See total interest earned vs total contributions

Pro Tip

Start investing as early as possible. Thanks to compound interest, even small monthly contributions can grow dramatically over decades. The difference between starting at 25 vs 35 can mean hundreds of thousands of dollars by retirement.

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