Free calculatorMost helpful for Strategists
Compound Interest Calculator
See how a starting balance and monthly contributions can grow over time.
Compound interest
Starting amount
Monthly contribution
Years
Average annual return
The details behind your number
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.
| 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
| 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
| 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 first step
Two people can get this exact result and need totally different first steps. Your Money Type tells you which one is 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 First Step 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.
Common questions
Example with hypothetical numbers: $1,000 to start plus $200 a month for 10 years at an 8% average annual return projects to about $38,809. You contribute $25,000 and growth adds about $13,809. Add more years to see how much the later years add.
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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