Wealth Calculator
Compound growth turns consistent saving into significant wealth. Enter your current savings, monthly contribution, and expected return to see exactly when you'll cross the $500K, $1M, and $2M milestones — and how much of it is your money vs. investment growth.
Project your wealth milestones and see a year-by-year portfolio growth chart.
How Wealth Compounds Over Time
Compound growth is the process where investment returns generate their own returns. A 7% annual return on $100,000 gives you $7,000 in year one. In year two, you earn 7% on $107,000 — which is $7,490. The next year: 7% on $114,490. Each year the base grows, so the same percentage generates more dollars. Over decades, this compounding effect becomes the dominant driver of wealth — dwarfing the original contributions that started the process.
The rule of 72 gives you an intuitive feel: at 7% return, your money doubles every 10 years (72 ÷ 7 = 10.3). $35,000 today becomes $70,000 in 10 years, $140,000 in 20 years, and $280,000 in 30 years — even with no additional contributions. Add $800/month throughout, and the 30-year balance exceeds $1 million.
The Three Levers of Wealth Building
Starting balance: Every dollar you have invested today works for the entire remaining horizon. $50,000 at age 30 becomes roughly $380,000 at 65 (7% return, no contributions) — through pure compounding. This is why paying off high-interest debt and investing the freed cash flow matters so much in your 20s and 30s.
Monthly contribution: Consistent contributions are the engine of wealth for most people. The amount matters, but the habit matters more. People who automate contributions capture gains in every market environment (dollar-cost averaging) and avoid the temptation to time the market. Increasing contributions by just 1% of income annually — as raises come in — compounds into significant additional wealth over decades.
Rate of return: A 1% difference in annual return, sustained over 30 years, changes the outcome dramatically. At 6% annual return, $800/month for 30 years grows to $804,000. At 7%, it's $1,004,000. At 8%, it's $1,264,000. You can't control market returns directly, but you can control costs — minimizing expense ratios (low-cost index funds at 0.03%–0.10% vs. 1%+ for active funds) is the closest thing to a guaranteed return improvement.
| Monthly Savings | Years to $1M | Total Contributed | Investment Growth |
|---|---|---|---|
| $500/mo | 33 yrs | $198,000 | $802,000 |
| $800/mo | 29 yrs | $278,000 | $722,000 |
| $1,500/mo | 23 yrs | $414,000 | $586,000 |
| $2,500/mo | 18 yrs | $540,000 | $460,000 |
To calculate your specific FIRE number — the savings target at which you can retire based on your actual expenses — use the FIRE Number Calculator. For retirement-specific projections including Social Security, see the Retirement Calculator.
Frequently Asked Questions
How long does it take to become a millionaire?
Starting from zero: saving $800/month at 7% return takes about 29 years to reach $1M. Saving $1,500/month takes 23 years. Starting with $50,000 already saved and contributing $800/month at 7% takes about 22 years. Each year you start sooner meaningfully shortens the timeline due to compound growth.
What is a realistic return to assume?
For diversified stock/bond portfolio planning: 6%–7% annually after inflation is a common conservative assumption. The S&P 500 has historically averaged ~10% nominally or ~7% after inflation. Using 7% in real (inflation-adjusted) terms keeps your projections grounded in today's purchasing power rather than inflated future dollars.
Does starting balance or monthly savings matter more?
Early on, monthly contributions drive most of the growth. After 15–20 years, compound growth on existing balance overtakes contributions as the primary driver. This is why both matter: build the balance early (even small amounts), then maintain consistent contributions so compound growth has the largest possible base to work on.
How much do I need to save to become a millionaire?
At 7% return for 30 years starting from zero: ~$820/month. For 25 years: ~$1,150/month. For 20 years: ~$1,700/month. Each decade you wait roughly doubles the required monthly savings. This calculator shows the exact timeline for your specific starting balance and contribution amount.
Is $1 million enough to retire on?
At a 4% sustainable withdrawal rate, $1M generates $40,000/year ($3,333/month) in portfolio income. Whether that's enough depends entirely on your expenses and other income sources (Social Security, pension, rental income). For many, $1M is a milestone but not the full retirement target. Calculate your FIRE number (25× annual expenses) for your personal retirement target.
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