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Simple Save vs Invest Calculator

Two sliders show why investing usually beats saving.

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In 20 years, investing wins by

$19,989

$500 to start + $50 a month · HYSA at ~4% vs S&P 500 at ~10%

If you save it

$19,288

At ~4% per year · +$6,788 growth

If you invest it

$39,277

At ~10% per year · +$26,777 growth

You'd only put in $12,500 of your own money. The rest comes from growth.

Try a what-if

Saved vs invested, year by yearThe gap between the two lines = the cost of leaving your money in cash.
Year 1Year 3Year 5Year 7Year 9Year 12Year 15Year 17Year 20$0$10,000$20,000$30,000$40,000
  • Saved
  • Invested

Your plan

Even $100 is a great start. Don't worry — this isn't locked in.

Even small amounts grow, thanks to .

Time is your biggest superpower. The longer you let it sit, the bigger the snowball. (We're not adjusting for here — both numbers are in today-style dollars.)

Two ways to grow your money: (a savings account today pays about ) and . This little tool shows the difference.

Wait, why such a big difference?

Saving in an HYSA earns about 4% a year. Safe and steady, but slow. Investing in something like the S&P 500 has averaged about 10% a year over many decades. That gap might sound small — but it year after year, so over decades it becomes huge.

The catch: investing goes up and down. Some years it loses money. The people who win are the ones who stay calm, keep adding a little each month, and don't pull out when things look scary.

Want to see the full picture with fees, inflation adjustment, and other investments? Click “Show me the math” at the top of this page.

Next steps

The simplest version of the savings-vs-investing question: two sliders (amount + years), one chart. Strip away the fees and inflation toggles and you can still see the gap clearly — investing pulls dramatically ahead of saving over decades. This calculator exists to make the concept stick before you graduate to the advanced version.

How this calculator works

  1. Drag the amount slider to set how much you have.
  2. Drag the years slider to set how long until you'd want the money.
  3. Read the gap. The chart shows savings (a flat-ish line) vs investing (a curve that accelerates).
  4. Ready for more detail? Switch to the advanced 'Savings vs Investing' calculator above for fees, inflation, and contributions.

savings = P × 1.04^t + C × [(1.04^t − 1) / i₄] vs investing = P × 1.10^t + C × [(1.10^t − 1) / i₁₀] i = (1 + annual rate)^(1/12) − 1

Two compound-interest curves at typical rates: ~4% APY for a top high-yield savings account and ~10% a year for the S&P 500 (its long-run nominal average — about 7% after inflation). Both are annual growth rates, compounded monthly at the rate that grows your money by exactly that much in a year, and your monthly deposits go into both. The gap between them widens dramatically as t grows.

P
Amount you start with
C
What you add each month
i₄, i₁₀
Monthly rate for 4% and 10% a year
t
Time in years

Frequently asked questions

Why does investing usually beat saving?

Savings accounts barely keep up with inflation. Stock index funds have historically returned roughly 10% a year before inflation (about 7% after), compounding into a much larger gap over decades.

Is investing risky?

Yes, in any single year — markets can drop 30% or more. But over 20+ years, broadly diversified portfolios have historically grown.

Sources used in this calculator

Reviewed by the Money Scale editorial team. How we source our data

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