Savings & growth
Compound Interest Calculator
See what steady contributions actually turn into over time — and who's counting on that number.
Interactive tool
Compound Interest Calculator
Investment growth with monthly contributions — final balance, contributions vs. interest earned, and a year-by-year table.
Historical S&P 500 average: ~10% nominal / ~7% real after inflation (FRED long-run average). Past returns don't guarantee future results.
Final balance after 30 years
$691,150
- Total contributions
- $190,000
- Total interest earned
- $501,150
- Interest as % of final balance
- 72.5%
Contributions vs growth
Frequently asked
What return rate should I use?
There's no guaranteed number. The S&P 500's long-run historical average is roughly 10% nominal (about 7% after inflation, per FRED long-run data), but any given year — or decade — can land far from that average. Past returns don't guarantee future results.
Does compounding frequency (monthly vs. annually) matter much?
It matters less than the rate and time horizon, but more-frequent compounding does modestly increase the final balance at the same nominal rate, since interest starts earning its own interest sooner.
How does this connect to insurance?
It doesn't have to — this is a general savings-growth tool. But a growing balance usually has people counting on it: a spouse, kids, a business partner. If nobody depends on that plan continuing, you may not need coverage; if someone does, that's the gap a life insurance policy is built to close.