Compound interest calculator

Strip dividends out of the picture and look at compounding on its own: a starting lump sum, a monthly deposit and a steady annual return. It is the baseline every dividend strategy is ultimately compared against.

Your result

Final value

$0

after 20 years

You contributed

$0

initial + monthly deposits

Interest earned

$0

growth did this part

Growth multiple

0×

final value per $1 contributed

Dividends are one way a portfolio earns that annual return. See what happens when the return arrives as reinvested income instead in the main dividend calculator →

Why compounding does the heavy lifting

Compounding means your returns start earning returns of their own. With dividend reinvestment the loop is visible: each payout buys more shares, those shares pay their own dividends, and the curve bends late — which is why time matters more than timing.

1

What you put in

An initial amount plus regular contributions. Every dollar added buys more income-producing shares, so contributions made early in the timeline matter most.

2

What the investment pays

Dividend yield, dividend growth and share price growth working together. Each one compounds on a base that the others keep enlarging.

3

How long it runs

The one lever you cannot buy back later. At an 8% return, a ten-year head start more than doubles the end result all by itself.

# $1,000 growing at a steady 10% a year
year 1 = $1,100 · year 2 = $1,210 · year 10 ≈ $2,594
year 20 ≈ $6,727 · year 30 ≈ $17,449
rule of 72: 72 ÷ your return ≈ years to double — at 8%, about 9 years

Look at where the growth happens: more than half of the final value in that example arrives in the last decade. The calculator above runs the same maths with your own numbers — your starting amount, your monthly contributions, with or without reinvestment — so you can watch the curve bend for your situation instead of a textbook one.

Frequently asked questions

Quick answers about compounding.

Is dividend compounding different from compound interest?

The engine is the same — growth on growth. The difference is the mechanism: interest compounds automatically inside an account, while dividend compounding happens because each payout buys fractional shares that pay dividends of their own under a DRIP.

How much difference does reinvesting really make?

Over 20–30 years it is usually the single biggest factor after contributions. Our DRIP vs taking the cash comparison runs the two side by side over 20 years.

What return should I assume?

Run the calculator twice — once with a hopeful rate and once with a cautious one. If the plan still works at the cautious rate, it is a plan.

Related calculators

Compounding from a different angle.

Compound interest calculator

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