Compound Interest & Monthly Deposit Calculator — ZYCalculator

A compound interest calculator projects future investment value by computing interest earned on both the initial principal and all previously accumulated interest.

Formula & Method

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

How to Use

  1. Enter Starting Principal: Set initial deposit and recurring monthly investment amount.
  2. Set Rate & Compounding Frequency: Choose annual interest percentage and compounding period (monthly, quarterly, annually).
  3. Review Donut Chart & Export CSV: Inspect total growth vs invested capital and download full yearly breakdown.

Frequently Asked Questions

What is compound interest and how does it differ from simple interest?

Compound interest earns interest on both the initial principal deposit and all previously accumulated interest. Simple interest only pays interest on the original principal balance.

How do regular monthly deposits accelerate compound growth?

Adding regular monthly contributions continuously increases the base balance upon which compounding operates, multiplying your future accumulated wealth exponentially over 10 to 30 years.