Compound Interest Calculator

The Beginner's Guide to Financial Calculators: Loans, Interest, and Investment Math

How mortgage payments, compound interest, and the Rule of 72 are actually calculated, with real worked examples.

How Compound Interest Really Grows Your Money

The compound interest formula explained with a monthly-contribution example and why starting early matters more than the rate.

How a $500 Monthly Contribution Becomes a Seven-Figure Retirement

The compound growth math behind long-term retirement savings, and why consistency matters more than perfect timing.

How Much You Actually Need to Save Each Month to Hit a Goal

The math behind working backward from a savings target to a required monthly contribution, with a real example.

Simple Interest vs. Compound Interest: The Formula Difference That Matters

Why simple interest grows in a straight line while compound interest curves upward, with a side-by-side example.

How CAGR Smooths Out Volatile Investment Returns

The Compound Annual Growth Rate formula explained, showing why it differs from a simple average of yearly returns.

Present Value and Future Value: Two Sides of the Same Formula

How present value and future value calculations mirror each other, with worked examples in both directions.

Planning for Retirement in Your 40s: What the Compounding Math Actually Shows

A real walkthrough of retirement projections starting mid-career, showing how existing savings and new contributions both compound toward the same goal.