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Savings vs Investing Calculator

Compare a high-yield savings account against an index-fund portfolio. See the real, inflation-adjusted gap over 5, 10, and 30 years — sourced data, free, no signup.

Last reviewed: · Reviewed by the Money Scale editorial team · How we source our data

Power mode. Every input exposed, every assumption sourced, charts and shareables.

Savings vs Investing
The flagship aha-moment calculator. Compare a savings account to a long-run market vehicle, side by side.
Real $

$10,000

$500

Horizon is set by the time scrubber below the chart (1–40 years).

Savings account

0.38% APY

Default: FDIC national avg 0.38%. Source

Investment

Avg long-run return: 10%

0.10% / year

Compounding:

Showing nominal dollars.

Guess first — what will the investment side be worth in 20 years?

Your guess$50,000
$0$893,277

Sources used in this calculator

All defaults are sourced from public US data. Verify any number before making decisions.

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, inflation, and taxes. Most online calculators only show the nominal numbers — ours adjusts for the things that actually change your purchasing power, so the answer reflects real dollars, not just bigger numbers on a screen.

Free, private, and no signup

Money Scale is built the opposite way from the big finance sites: the numbers you enter never leave your device, and there's nothing to sign up for.

  • Your numbers stay privateEvery calculation runs in your browser. We never receive or store your salary, balances, or inputs.
  • Always freeNo paywall, no upsell to a calculator that actually works.
  • No login, no emailUse every tool instantly — we never gate results behind a signup.
  • Sourced defaultsStarting rates and assumptions cite real data, not made-up numbers.

Keeping it free and unfunded by your data still costs us hosting and data fees every month. If a calculator here helped, you're welcome to buy us a coffee — completely optional, and nothing here is ever locked behind it.

How this calculator works

  1. Enter the amount you have available to either save or invest right now.
  2. Set a monthly contribution. The calculator applies the same amount to both scenarios so the comparison is apples-to-apples.
  3. Pick a savings APY (4–5% is realistic for top online banks today) and an investment return (7% real / 10% nominal is the long-run S&P 500 average per NYU Stern / Damodaran).
  4. Add expected investment fees. Broad-market index funds run 0.03%–0.20%; advisor or actively-managed funds can be 1%+.
  5. Set your inflation assumption (3% is the long-run BLS CPI-U average) and a time horizon — 5, 10, and 30 years are the milestones that tend to flip people's intuition.
  6. Compare the real-dollar gap. The chart shows how investing pulls away from savings as the horizon stretches, even after fees.

FV = P × (1 + r − f − i)^t + C × [((1 + r − f − i)^t − 1) / (r − f − i)]

Standard future-value of a series with an initial deposit. We subtract fees and inflation from the gross return up front so the answer is in real, today-purchasing-power dollars — the gap between savings and investing is mostly hidden until you do this.

FV
Future value in today's dollars
P
Initial deposit (principal)
C
Recurring monthly contribution (annualized inside the formula)
r
Annual gross return
f
Annual fee drag (expense ratio + advisor)
i
Inflation rate
t
Time in years

Frequently asked questions

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.

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Free, no signup, runs in your browser. Educational modeling only — not financial advice.

Sources
Every default value is sourced. Verify anything.
National Avg Savings APY — 0.38% (as of May 2026)FDIC National Rates and Rate Caps High-Yield Savings (typical) — 4% (as of May 2026)FDIC National Rates + reported HYSA APY (top online banks) S&P 500 — 10% (as of 2026 (1928–2025 dataset))NYU Stern (Damodaran) — S&P 500 Annual Returns 1928–2025 Total US Stock Market — 9.7% (as of 2026)CRSP US Total Market Index (long-run avg) 10-Year Treasuries — 4.5% (as of May 2026)Federal Reserve FRED — 10-Year Treasury (DGS10) US Real Estate — 4.2% (as of 2026)S&P CoreLogic Case-Shiller US National Home Price Index (FRED) Gold — 7.8% (as of 2026)World Gold Council historical price data Long-run CPI Inflation — 3% (as of 2026)Bureau of Labor Statistics — CPI-U (long-run avg) 30-Year Fixed Mortgage — 6.36% (as of May 2026)Freddie Mac PMMS — 30-Year Fixed Rate Mortgage Average Credit Card APR (avg, accounts assessed interest) — 21.52% (as of May 2026 release (March 2026 data))Federal Reserve G.19 — Consumer Credit Auto Loan (60-month new car, avg) — 7.52% (as of May 2026 release (March 2026 data))Federal Reserve G.19 — Consumer Credit Personal Loan (24-month unsecured, avg) — 11.4% (as of May 2026 release (March 2026 data))Federal Reserve G.19 — Consumer Credit Federal Direct Subsidized/Unsubsidized (Undergrad) — 6.52% (as of AY 2026-27)US Dept of Education — Interest Rates and Fees for Federal Student Loans HELOC (typical introductory rate) — 7.26% (as of May 2026)Bankrate — Current HELOC Rates 12-month CD (top online rate, typical) — 4.1% (as of May 2026)FDIC + reported top online CD rates Mortgage Refinance Closing Costs (typical) — 3% (as of 2026)Freddie Mac — Cost of Refinancing College Tuition Inflation (long-run avg) — 4% (as of AY 2025-26 (Nov 2025 publication))College Board — Trends in College Pricing 2025