DRIP Math Guide

What Is a Dividend Reinvestment Plan (DRIP)?

A Dividend Reinvestment Plan, or DRIP, is a program that automatically reinvests cash dividends into additional shares of the same stock, often without brokerage commissions. Instead of receiving a cash payout, the investor accumulates more shares, which then produce their own dividends. This creates a compounding loop: more shares generate more dividends, which buy more shares.

The mathematics are straightforward in any single year but powerful across decades. If you hold 100 shares paying a $3 annual dividend, you receive $300. Reinvested at a $60 share price, you acquire 5 additional shares. Next year, you earn dividends on 105 shares, and the cycle accelerates, especially when the company raises its dividend.

Understanding Yield on Cost (YoC)

Yield on Cost measures your dividend income against the price you originally paid, not the current market price. The formula is:

Yield on Cost = (Annual Dividend per Share ÷ Original Cost Basis per Share) × 100

If you bought shares at $50 and the dividend has grown to $4 per year, your Yield on Cost is 8%, regardless of whether the stock now trades at $100 or $200. YoC reveals the income advantage of holding dividend growth stocks over time, as your effective yield on invested capital rises each year the company increases its payout.

Dividend Aristocrat Investing

Dividend Aristocrats are companies in the S&P 500 that have increased their dividends for 25 or more consecutive years. These companies tend to have durable business models, strong cash flows, and a management culture committed to returning capital to shareholders. Investors in aristocrats benefit from a rising income stream that historically outpaces inflation.

The strategy pairs naturally with DRIP. Reinvesting aristocrat dividends during accumulation years builds a large share base, after which an investor can switch to receiving cash dividends as a passive income stream. This transition, often planned for retirement, is when the years of compounding pay off as a reliable monthly paycheck.

The Inflection Point

A key concept visible in this calculator's chart is the inflection point: the year when annual dividends earned exceed annual contributions. Before this point, portfolio growth is driven mainly by your savings. After it, dividends do the heavy lifting. Reaching the inflection point earlier depends on a higher starting yield, faster dividend growth, and consistent contributions. This is the essence of dividend growth investing, and the reason time in the market matters more than timing the market.