Project the future value of an investment from a starting amount, monthly contributions, expected return, and time horizon.
Enter your starting amount, the monthly contribution you plan to make, an expected annual return, and your time horizon in years. The calculator runs the future value formula month-by-month and plots two lines: cumulative contributions and the projected future value. The gap between them is your investment growth.
For an investment with both an initial deposit and ongoing contributions:
PV is present value (starting amount). PMT is the periodic contribution. r is the periodic rate. nis the number of periods. The first term grows your starting amount; the second term grows each contribution from the date it’s made.
Future value is the projected dollar amount that an investment will be worth at a specific point in the future, based on an assumed rate of return. It's the most common output in retirement and goal-planning math: "If I invest $X today and add $Y per month at Z% return, how much will I have in N years?" The calculator above answers exactly that.
For a single lump sum: FV = PV × (1 + r)^n, where PV is present value, r is the periodic rate, and n is the number of periods. For an investment with regular contributions, the formula adds an annuity term: FV = PV × (1 + r)^n + PMT × [((1 + r)^n − 1) ÷ r]. The calculator above uses the monthly version of this formula.
For long-term US stock-market investing, the historical average is roughly 10% nominal (before inflation) and ~7% real. Most planners model 6–8% as a conservative-to-moderate assumption to avoid over-promising. For a bond-heavy portfolio, 4–5% is closer. Anything above 12% as a long-run assumption is optimistic.
Future value asks "what will today's money grow to?" Present value asks the reverse: "what is a future amount of money worth today?" PV discounts future dollars at the rate of return, while FV grows present dollars at the same rate. Both use the same underlying compound interest math.
For long-horizon planning, yes — at least mentally. A future balance of $1M in 30 years is not worth $1M in today's purchasing power. To work in "real" (inflation-adjusted) dollars, subtract inflation from your assumed return: instead of 10%, use 7%. The calculator gives you nominal future value; subtract ~3% from your rate input to see the real-dollar version.
Functionally none. Both project an investment's growth from a starting amount, periodic contributions, and a return rate. "Compound interest calculator" is the term used in banking; "future value calculator" is the term used in investing and corporate finance. Same math, different framing.
They're directionally useful, not literally accurate. Real investment returns vary year to year — the S&P 500's 10% average hides single years of -37% (2008) and +32% (2013). Future value projections smooth this volatility and assume a constant return. Use them to compare scenarios ("what if I add $200 more per month") rather than to predict an exact dollar amount 30 years out.
Significantly. The same $1M future value is worth ~$700k after federal long-term capital gains tax (15-20%), or as little as $500k in a high-tax state if held in a taxable account. The same investment in a Roth IRA or Roth 401(k) is worth the full $1M after retirement age. Account location matters as much as asset selection — sometimes more.
Every dollar you don’t invest today has a future-value cost. At 8% over 30 years, every $1 invested today is worth ~$10 then. A $5,000 vacation isn’t just $5,000 — it’s a $50,000 retirement-bedroom decision.
The HomeCFO Program rewires how you think about today’s decisions in future-value terms — without making you feel bad about the vacation.
Book an intro session