Adjust your parameters and visualize your financial future.
Retirement portfolio target: $1,500,000 — based on 4% annual withdrawal of $60,000 in expenses.
Optional
Save, share, track, and compare — everything you need on your path to FI
Projection based on current scenario parameters
The dashed vertical line marks when your portfolio is projected to reach your retirement target — the balance at which a 4% annual withdrawal (the Bengen safe withdrawal rate) covers your annual expenses indefinitely without depleting principal. Projections assume continued contributions and growth and do not model post-retirement withdrawals.
Want to save this projection?
Create a free account to save scenarios and track your progress over time.
An investment growth calculator helps you visualize the long-term impact of compound interest on your portfolio. Whether you're just starting out or optimizing an existing investment strategy, understanding how your money grows over time is the foundation of sound financial planning.
Compound interest is often called the eighth wonder of the world, and for good reason. When your investments generate returns, those returns are reinvested and begin generating their own returns. Over decades, this compounding effect transforms modest contributions into substantial wealth. A 25-year-old who invests $300 per month at a 7% annual return will have over $900,000 by age 65 — the majority of which comes from compound growth rather than actual contributions.
Both your starting balance and your regular contributions matter, but they work differently. A larger starting balance benefits from compounding immediately. Ongoing contributions, on the other hand, dollar-cost average into the market over time and each contribution starts its own compounding journey. Our investment growth calculator handles both variables simultaneously, giving you an accurate picture of how your specific financial situation will evolve.
Your expected rate of return is the most sensitive variable in any long-term projection. A difference of just 1–2% annually can mean hundreds of thousands of dollars over a 30-year period. We recommend modeling multiple scenarios — a conservative case (5%), a base case (7%), and an optimistic case (9%) — to understand the range of possible outcomes rather than relying on a single projection.
Most investment calculators treat contributions as annual lump sums, which understates the true benefit of regular investing. WealthAssist's calculator applies the correct Future Value of an Annuity formula for each frequency — monthly, quarterly, or annually. This means if you contribute $500 per month, each individual contribution starts compounding at the monthly rate for the remainder of the year, not just annually.
An investment growth calculator is most powerful when combined with a retirement target. In the Retirement Parameters section, enter your expected annual expenses and withdrawal rate to calculate the exact portfolio size you need to retire. The calculator will show your year-by-year percentage progress toward that target, and the chart will mark the exact age at which your portfolio reaches your retirement goal.
The best financial plans aren't built on a single projection — they explore multiple paths. With a WealthAssist Pro account, you can save your current assumptions as a named scenario, create alternative versions with different contribution amounts or return rates, and compare any two scenarios side by side. This lets you model decisions like "what if I increased my monthly contributions by $200?" or "how does retiring at 55 vs. 60 affect my portfolio?"
The calculator uses the Future Value of an Annuity formula to compute year-by-year portfolio growth. It accounts for your starting balance, periodic contributions (monthly, quarterly, or annually), and expected annual rate of return. Unlike simple interest calculators, it applies compounding at the correct frequency — so monthly contributions compound monthly, not just annually.
Compound interest means you earn returns not just on your original principal, but on all previously accumulated gains. Over long time horizons, this creates exponential growth. For example, $50,000 growing at 7% annually for 35 years becomes approximately $533,000 with no additional contributions — purely from compounding. Add $500/month and that figure exceeds $1.5 million.
The right rate depends on your investment strategy and risk tolerance. A diversified index fund portfolio has historically delivered 7–10% annually over long periods before inflation. A more conservative mix of stocks and bonds might use 5–6%. We recommend running multiple projections with different rates to understand the range of possible outcomes.
More frequent contributions generally result in higher final balances because money enters your portfolio sooner and starts compounding earlier. Monthly contributions outperform the equivalent annual lump sum by a small but meaningful margin over long periods. Our calculator correctly computes the compounding difference between monthly, quarterly, and annual contribution frequencies.
Yes — create a free WealthAssist account to save your projection as a named scenario. With a Pro subscription, you can save unlimited scenarios, compare two projections side by side, and set a default scenario that loads automatically when you log in.
Portfolio balance refers only to your investment accounts. Net worth includes your portfolio balance plus any home equity (property value minus mortgage balance). If you own a home, you can enter your property details in the Home Equity section to see your projected total net worth over time.