Investment Calculator
Project the future value of an investment with a starting principal, regular contributions and an expected annual return — or solve backward for the contribution needed to reach a target.
How to use the Investment Calculator
- Enter your inputs into the Investment Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The investment growth formula
FV = PV(1 + r)^n + PMT · [((1 + r)^n − 1) / r]
PV is the present value, r is the periodic return rate, n is the number of periods and PMT is the periodic contribution. For monthly contributions, divide annual rate by 12 and multiply years by 12.
Worked example
$10,000 starting balance with $500 monthly contributions over 20 years at 7% annual: FV = 10,000×(1.0058)^240 + 500×[((1.0058)^240 − 1)/0.0058] ≈ $300,400. Total contributions: $130,000. Investment growth: $170,400.
Frequently asked questions
Should I use nominal or real returns?
Nominal returns are what the market actually delivers; real returns subtract inflation. For long-term planning in today's purchasing power, a 4–5% real return is conservative.
How does compounding frequency affect the result?
Monthly compounding produces slightly more than annual at the same rate. The difference is small over short periods and meaningful over 20+ years.
What about taxes and fees?
Subtract expected fund expense ratios and tax drag from the assumed return. A 0.5% expense ratio over 30 years can cost 10%+ of the final balance.