What is compound interest?

Growth that earns growth. Each period, the return applies to your balance plus what you already earned, not just the money you put in.

What return should I assume?

A long-term stock-heavy plan is often modeled around 7 to 8% a year. Savings accounts use a much lower rate. This is a projection, not a promise.

Free Compound Interest Calculator

Compound interest

Starting amount

$1,000

Monthly contribution

$200

Years

10 years

Average annual return

8%

Projected value

$38,809

You would contribute about $25,000. The rest is growth. Estimate only.

Total balanceWhat you put in

After 10 years: about $38,809. You put in $25,000 and growth adds $13,809.

Where the final balance comes from

Your money, split by source.

Starting amount$1,000 (3%)
Monthly contributions$24,000 (62%)
Interest earned$13,809 (36%)

Balance after 10 years$38,809

What if the return were different?

Same deposits, same timeline. Returns are assumptions, not promises.

Final balance at different returns
Return	Final balance	Interest earned	Difference
6% a year	$34,595	$9,595	$4,214 less
8% a yearYou	$38,809	$13,809	Your plan
10% a year	$43,676	$18,676	+$4,867

The cost of waiting

Same end date and same deposits, just a later start.

Waiting 1 year costs: $5,273
Waiting 5 years costs: $22,624
Starting 5 years sooner adds: $33,706

Final balance by start time
Timing	Final balance	Difference
Start 5 years sooner (15 years)	$72,515	+$33,706
Your plan (10 years)You	$38,809	Your plan
Wait 1 year	$33,535	$5,273 less
Wait 5 years	$16,185	$22,624 less

Milestones along the way

When your balance first passes each mark.

$10K balanceIn 3y 3m
$25K balanceIn 7y 3m
$50K balanceNot in 10 years

Year by year breakdown

Compound interest year by year
Year	Total put in	Interest that year	Balance
Year 1	$3,400	$173	$3,573
Year 2	$5,800	$387	$6,360
Year 3	$8,200	$618	$9,377
Year 4	$10,600	$868	$12,646
Year 5	$13,000	$1,140	$16,185
Year 6	$15,400	$1,433	$20,019
Year 7	$17,800	$1,752	$24,170
Year 8	$20,200	$2,096	$28,666
Year 9	$22,600	$2,469	$33,535
Year 10	$25,000	$2,873	$38,809

Your next step

Same numbers, different next move

Two people can get this exact result and need totally different first steps. Your Money Type tells you which one is yours.

Strategist“My plan works. I just want it to grow faster.”
Spender“The money is gone before I think about it.”
Saver“I save it. Then it just sits there.”
Scrambler“Every payday I’m guessing what gets paid first.”

Find my Money TypeFree, about 2 minutes

Already know yours?

How It Works

01
Enter your starting amount and your monthly contribution.
02
Set the number of years and an average annual return.
03
See the projected value at the end of that time.

The 4 Money Types

The Math Is the Same. Your Next Move Isn't.

Spenders, Savers, Scramblers, and Strategists each need a different first fix. The free quiz tells you which type you are, so you know what to do with this number.

Find My Money Type

Common questions

: Growth that earns growth. Each period, the return applies to your balance plus what you already earned, not just the money you put in.
: A long-term stock-heavy plan is often modeled around 7 to 8% a year. Savings accounts use a much lower rate. This is a projection, not a promise.

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Compound Interest Calculator