How to Calculate Dividend Reinvestment: Step by Step

What dividend reinvestment is

A dividend is cash your shares earn, and dividend reinvestment — DRIP — is the choice to spend that cash on more shares instead of taking it out. The key concept: each dividend buys a few more shares, and those shares pay the next dividend. The share count grows every year, and the growing share count earns a growing dividend. With 100 shares at $50.00 and a $2.00 dividend, by year 10 the shares have become 140.23 and the portfolio is worth $13,792.60 — $1,441.26 more than taking the cash.

Step 1: Start with what you own

Multiply your shares by the share price. With 100 shares at $50.00, the cost is $5,000.00. That cost is the denominator of everything that follows: the yield on cost is the dividend divided by this $50.00, and the total return is the final value minus this $5,000.00, divided by it. With 50 shares the final value is $6,896.30; with 500 it is $68,962.98 — the percentages are the same at any size.

Step 2: The dividend each year

The dividend per share grows at the rate you enter. At 5% a year, a $2.00 dividend becomes $2.10 in year 2, $2.21 in year 3, and $3.10 in year 10 ($2.00 × 1.05^9). The dividend is paid at year-end on the shares held during that year, so more shares mean a bigger dividend. With no dividend growth the value is $12,974.08; with 10% it is $14,908.09. With a $4.00 dividend the value is $19,127.96. With no dividend at all the value is $9,835.76 and reinvesting adds nothing.

Step 3: The price each year

The share price grows at the rate you enter, and the dividend is reinvested at that year’s price. At 7% a year, $50.00 becomes $53.50 in year 1 and $98.36 in year 10 ($50.00 × 1.07^10). A higher price means each dividend buys fewer shares: at $25.00 the share count reaches 194.47 and the value is $9,563.98; at $100.00 it reaches only 118.59 and the value is $23,328.09. A cheaper share buys more shares with each dividend, so the price reverse has two roots and the $82.7754 answer is the higher-price one. With 0% price growth the value is $8,166.84; with 12% the price reaches $155.29 and the value is $20,301.93.

Step 4: The shares grow

Each year the dividend buys more shares at that year’s price: shares_t = shares_(t−1) × (1 + D_t / P_t). In year 1 the $2.00 dividend on 100 shares is $200.00, buying 3.74 shares at $53.50. By year 10 the 100 shares have become 140.23 — 40.23 extra shares, bought with dividends alone, each earning the next dividend. With a $4.00 dividend the count reaches 194.47; with no dividend it stays 100.00.

Step 5: The final value — DRIP vs cash

Multiply the final shares by the final price: 140.23 × $98.36 is $13,792.60. Had you taken the cash, the dividends add up to $2,515.58 and the 100 shares are worth $9,835.76 — a total of $12,351.34. Reinvesting is worth $1,441.26 more, and the advantage grows with time: after 5 years it is only $251.84; after 20 years $9,965.69; after 30 $37,874.24. The longer the run, the more the compounding shows.

Step 6: Yield on cost and total return

Your $2.00 dividend on a $50.00 cost is 4.00% in year 1, but by year 10 the dividend is $3.10 on the same cost — a yield on cost of 6.21%, rising because the dividend grows while your cost stays fixed. After 20 years it is 10.11%; after 30 it is 16.46%. The total return is ($13,792.60 − $5,000.00) ÷ $5,000.00 × 100 = 175.85%; after 20 years it is 618.55%; after 30 years it is 1684.47%.

The worked example

100 shares, $50.00 a share, $2.00 dividend, 5% dividend growth, 7% price growth, 10 years. Cost: 100 × $50.00 = $5,000.00. Price in year 10: $50.00 × 1.07^10 = $98.36. Dividend in year 10: $2.00 × 1.05^9 = $3.10. Shares: 100 growing by (1 + D_t / P_t) each year = 140.23. Value: 140.23 × $98.36 = $13,792.60. Cash dividends: 100 × the yearly dividends = $2,515.58. Value without DRIP: 100 × $98.36 + $2,515.58 = $12,351.34. Advantage: $13,792.60 − $12,351.34 = $1,441.26. Yield on cost: $3.10 ÷ $50.00 = 6.21%. Total return: ($13,792.60 − $5,000.00) ÷ $5,000.00 = 175.85%. Totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum.

Working backwards

145.01 shares (exact 145.0053) reach a $20,000 final value: at 145.01 shares the value is $20,000.64, at 145.00 it is $19,999.26. A share price of $82.78 (exact $82.7754) reaches $20,000 too — the upper root, since value(P) is U-shaped with a minimum below $50; at $82.78 the value is $20,000.88, at $82.77 $19,998.95. A $2.51 dividend (exact $2.5070) reaches $15,000: at $2.51 the value is $15,007.44, at $2.50 it is $14,982.72. Share-price growth of 11.81% (exact 11.8067%) reaches $20,000: at 11.81% the value is $20,005.09, at 11.80% it is $19,989.59. 7 years reach $10,000: at 6 years the value is $9,260.25, at 7 years it is $10,239.23. Dividend growth of 10.35% (exact 10.3489%) reaches $15,000: at 10.35% the value is $15,000.29, at 10.34% it is $14,997.63.

When the numbers change

At 20 years the value is $35,927.31 and the total return is 618.55%; at 30 years it is $89,223.28 and 1684.47%. A $25.00 share price gives $9,563.98, a $4.00 dividend $19,127.96, and 12% price growth $20,301.93. More shares, a bigger dividend, or more time raise the final value — and time raises it fastest.

What DRIP cannot do

Reinvesting does not make a bad stock good: it assumes the dividend is never cut and the price grows every year, yet a company can cut its dividend and the price can fall faster than dividends compound. It ignores taxes — every dividend is taxed whether you reinvest it or not — and it assumes fractional shares, which most brokers offer for DRIP. The model is a calculator, not investment advice.

How this connects

Run your own numbers with the dividend reinvestment calculator; for the dividend itself, see the dividend yield calculator; for the compounding behind it, see the compound growth calculator.