Savings vs Investing Calculator
Compare HYSA vs index funds after fees and inflation.
After 20 years, investing puts you ahead by
$285,551
- You put in
- $130,000
- Savings @ yr 20
- $135,437
- S&P 500 @ yr 20
- $420,988
Over 20 years you'd put in $130,000. Invested in the S&P 500, it grows to $420,988 — $285,551 more than the savings account, and 69% of it is growth.
Try a what-if
- Savings
- S&P 500
Drag to inspect any year
Year 20 of 40 · advantage $285,551
Your numbers
$10,000
$500
Same as dragging the year scrubber under the chart.
20 years
Investment
Avg long-run return: 10%
More optionsFees 0.10% · monthly · nominal $
0.10% / year
Savings
$135,437
S&P 500
$420,988
Next steps
The Savings vs Investing Calculator compares a high-yield savings account against a diversified index-fund portfolio across the same time horizon, accounting for fees and inflation. Both sides compound on the same footing — the savings APY and the long-run investment return are each treated as an effective annual rate — and one switch shows the result in today's purchasing power, so the answer reflects real dollars, not just bigger numbers on a screen. (It doesn't model taxes on interest or gains.)
How this calculator works
- Enter the amount you have available to either save or invest right now.
- Set a monthly contribution. The calculator applies the same amount to both scenarios so the comparison is apples-to-apples.
- Pick a savings APY (4–5% is realistic for top online banks today) and an investment (the S&P 500's ~10% nominal long-run average per NYU Stern / Damodaran, or a custom return).
- Add expected investment fees. Broad-market index funds run 0.03%–0.20%; advisor or actively-managed funds can be 1%+.
- Flip 'Real $' to see both balances in today's dollars (3%, the long-run BLS CPI-U average), and scrub the year — 5, 10, and 30 years are the milestones that tend to flip people's intuition.
- Compare the gap. The chart shows how investing pulls away from savings as the horizon stretches, even after fees.
i = (1 + r_eff)^(1/12) − 1, n = 12t
FV = P × (1 + i)^n + C × [((1 + i)^n − 1) / i]
r_eff = APY (savings) or r − f (investing)
today's $ = FV / (1 + π)^tStandard future value of monthly deposits plus an initial deposit. Both rates are effective annual rates — an APY already includes compounding, and a long-run '10% a year' return is an annual growth rate — so each is converted to the monthly rate that compounds to it over a year, (1 + r)^(1/12) − 1. Fees come off the investment return first. The 'Real $' view divides by (1 + π)^t so both balances are in today's purchasing power.
- FV
- Future value
- P
- Initial deposit (principal)
- C
- Recurring monthly contribution
- r
- Annual investment return (effective)
- f
- Annual fee drag (expense ratio + advisor)
- π
- Inflation rate (3% long-run CPI)
- t
- Time in years
Frequently asked questions
Should I save or invest right now?
Build a 3-to-6-month emergency fund in a high-yield savings account first, then invest the rest in a low-cost index fund for any goal more than five years away.
What return should I assume for investing?
A common long-run assumption for a global stock portfolio is 7% per year before inflation, or roughly 4–5% after inflation. The calculator lets you adjust this.
Are the numbers in this calculator guaranteed?
No. They are projections based on your inputs and historical averages. Real-world returns vary year to year. Treat the results as a planning guide, not a promise.
Sources used in this calculator
- FDIC National Rates and Rate CapsNational Avg Savings APY: 0.38% (as of May 2026)(opens in a new tab)
- FDIC National Rates + reported HYSA APY (top online banks)High-Yield Savings (typical): 4% (as of May 2026)(opens in a new tab)
- NYU Stern (Damodaran) — S&P 500 Annual Returns 1928–2025S&P 500: 10% (as of 2026 (1928–2025 dataset))(opens in a new tab)
- CRSP US Total Market Index (long-run avg)Total US Stock Market: 9.7% (as of 2026)(opens in a new tab)
- Federal Reserve FRED — 10-Year Treasury (DGS10)10-Year Treasuries: 4.5% (as of May 2026)(opens in a new tab)
- S&P CoreLogic Case-Shiller US National Home Price Index (FRED)US Real Estate: 4.2% (as of 2026)(opens in a new tab)
- World Gold Council historical price dataGold: 7.8% (as of 2026)(opens in a new tab)
- Bureau of Labor Statistics — CPI-U (long-run avg)Long-run CPI Inflation: 3% (as of 2026)(opens in a new tab)
- SEC Investor Bulletin — How fees and expenses affect your portfolioWhy fee drag is modeled(opens in a new tab)
Reviewed by the Money Scale editorial team. How we source our data
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