Dividend reinvestment calculator

What a DRIP grows to, how much the reinvestment itself adds over taking the dividends in cash, and the tax drag most DRIP calculators leave out by assuming a sheltered account.

How the math works

A DRIP is compound growth with a second engine bolted on. The share price grows on its own, and every dividend buys more shares, which pay their own dividends next time. The calculator runs it one year at a time.

Each year the price appreciates by the growth rate, the dividend per share is paid, and — in the reinvestment path — the after-tax dividend buys new shares at that year's price. Those new shares carry into the next year and are paid dividends of their own. That is the compounding. The ending balance is the final share count times the final price.

The dividend per share grows on its own rate, separate from the price. Set the two equal and the yield holds steady; let dividends grow slower than the price and the yield drifts down over time, which is roughly what has happened to the broad market.

The "taken as cash" figure runs the same holding but banks each dividend at a 0% return instead of reinvesting it. That is the honest floor: it isolates what the reinvestment itself did, with no assumption about what the idle cash might have earned elsewhere.

Worked example

Take $10,000 in a broad index fund, left alone for 30 years. The S&P 500's long-run nominal return of 10.2% is a total-return figure — it already assumes every dividend was reinvested. Split it into its parts: a 1.2% dividend yield and price appreciation of roughly 9% (10.2% total less the 1.2% yield). Hold the yield steady by growing the dividend at the same 9% as the price.

Reinvested in a sheltered account, the $10,000 grows to $184,267 — the same figure you get from $10,000 × 1.102³⁰, because total return and reinvested-dividend growth are the same calculation done two ways.

Now take the dividends as cash instead. The shares alone grow at 9% to $132,677, and the dividends banked along the way add $16,357, for $149,034. Reinvestment added $35,233 — about a fifth of the ending balance — on a yield that never rose above 1.2%. That is the case for turning the DRIP on and forgetting it.

When this calculator is wrong

The clean number above assumes a sheltered account. In a taxable brokerage account, a DRIP is quietly worse than the calculators suggest, in two ways they rarely mention.

Reinvested dividends are still taxed the year they're paid. The cash never touches your hand — it goes straight back into shares — but the IRS treats it as income all the same. So the reinvestment happens with after-tax dollars. A 1.2% yield taxed at the qualified-dividend rate of 15% reinvests at 1.02%, not 1.2%. Run the same 30-year example in a taxable account at that rate and the ending balance drops to $175,448 — roughly $8,819 less than the sheltered version, with $2,972 paid out in dividend tax along the way. Higher earners fare worse: the top qualified-dividend rate is 20%, and the Net Investment Income Tax adds another 3.8% above $200,000 of income for a single filer. Non-qualified dividends are taxed as ordinary income, up to 37%.

Every reinvestment is a new tax lot. A DRIP that reinvests quarterly for 30 years doesn't buy one position — it buys 120 tiny slivers of stock, each at a different price on a different day. When you sell, the cost basis is the sum of all of them, and if you want to sell only some shares you have to pick which lots go. The brokerage tracks it now, but it also means a DRIP holding is a thicket of small lots that complicates tax-loss harvesting and quietly triggers wash-sale rules if you buy the same fund elsewhere. None of the mainstream DRIP calculators surface this, because they model a sheltered account, where cost basis is never taxed and the lots never need tracking.

The other two limits are the ordinary ones. The yield is not guaranteed — a company can cut or suspend its dividend, and reinvesting into a single name concentrates that risk. And every rate here is a scenario, not a forecast; past performance has near-zero predictive power for future relative returns.

What to do with the result

If the money is in an IRA, a Roth, or a 401(k), turn reinvestment on and leave it. There is no tax to pay along the way, and the compounding runs at full strength — the sheltered number is the real one.

In a taxable account, reinvesting is still usually right, but treat the tax as a real cost and keep the paperwork simple. For a broad index fund the dividend is a small part of the return, so the drag is modest and the reinvestment still wins. For a high-yield single stock or a dividend-focused fund in a taxable account, the tax bites harder and the pile of tiny lots is worth avoiding — many investors there let the dividends land as cash and steer them into whatever they're buying next, which sidesteps the lot sprawl without leaving the money idle.

Common questions

What is a DRIP?

A dividend reinvestment plan automatically uses each cash dividend to buy more shares of the same holding, often fractional shares, instead of paying the dividend out as cash. The new shares earn their own dividends, which compounds the position over time.

Do I pay tax on reinvested dividends?

In a taxable account, yes — a reinvested dividend is taxed the year it's paid, exactly as if you'd taken the cash, even though you never see it. Qualified dividends are taxed at the long-term capital gains rates (0%, 15%, or 20%); non-qualified dividends are taxed as ordinary income. Inside an IRA, Roth, or 401(k) there is no tax on the reinvestment.

How much does reinvesting actually add?

It depends on the yield and the horizon. In the 30-year example above, a 1.2% yield reinvested added about $35,233 to a $184,267 ending balance — roughly a fifth. On a higher-yield holding, or over a longer horizon, the reinvested share of the total return is larger. Dividends have supplied about 40% of the S&P 500's total return since 1930.

Does reinvesting change my cost basis?

Yes. Each reinvested dividend is a purchase, so it adds to your total cost basis and creates a new tax lot at that day's price. A long-running DRIP builds up many small lots. Your broker tracks the basis, but it makes selling specific lots and harvesting losses more fiddly.

Should I reinvest or take the cash in retirement?

If you need the income to live on, take the cash — that's the point of holding dividend payers in retirement. If you don't need it yet, reinvesting keeps the compounding going. The calculator's gap between the two shows what you give up by spending the dividends instead of reinvesting them.