How to use it
- Enter Starting amount.
- Enter Annual rate %.
- Enter Years.
- Enter Compounds / year.
- Enter Monthly contribution.
The formula
A = P(1+r/n)ⁿᵗ + PMT·[((1+r/n)ⁿᵗ−1)/(r/n)]
Worked example
$10,000 at 7% for 20 years with $200/month grows to roughly $144,600.
Frequently asked questions
What is compounding?
Earning returns on past returns, not just the starting sum.
Does frequency matter?
More frequent compounding raises the result slightly.
Tips
- Time in the market beats timing the market.
- Reinvest returns to let compounding work.
- Keep fees low — they compound against you.
Key terms
- Compounding
- Earning returns on past returns.
- CAGR
- The smoothed annual growth rate.
- Yield
- Income as a percent of price.