Monthly investing

This tool pairs with "Dollar-cost averaging: steady beats clever". The behavioral case for investing monthly is made there; here is the basic account: invest a fixed amount each month at a steady assumed return, and after some years the balance splits into what you contributed and what compounding added on top.

Result

Investing 500 a month at an assumed 6% yearly return, compounded monthly, grows to about 81,237 after 10 years: 60,000 contributed, 21,237 from growth.

Ending value: 81,237
Total contributed: 60,000
Growth: 21,237

Chart: account value versus total contributions. The gap is the compounding contribution. Hold and drag across the chart, or use arrow keys, to read point by point.

Monthly investing spreads your entry prices; it does not remove the risk of falling markets. Not investment advice.

Assumptions & limits

The flat yearly return is a simplification for sizing, and real results depend on the path: monthly investing looks best when markets fall first and recover later, while a rising market rewards investing sooner. What the monthly habit reliably buys is discipline and a plan that matches how salaries arrive, not a mathematical edge. For your real account, measure with a money-weighted return (XIRR).