Finance
Investment Calculator
Project your investment growth with compound interest, monthly contributions, and inflation adjustment.
Enter investment details and click Calculate
How is this calculated?
FV = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]
Where: P = initial, r = annual rate, n = compounds/year, t = years, PMT = contribution
Inflation adjusted: real rate = (1 + nominal) / (1 + inflation) - 1FAQ
Frequently asked questions
How does compound interest work with investments?
Compound interest earns interest on both your principal and previously earned interest. Over time, this creates exponential growth — the longer you invest, the more powerful compounding becomes.
What is a realistic expected return rate?
The S&P 500 has historically returned about 10% annually before inflation (7% after). Bond funds return 4-6%. A diversified portfolio might target 7-8% for long-term planning.
How does compounding frequency matter?
More frequent compounding (daily vs annually) produces slightly higher returns because interest earns interest sooner. The difference is small but compounds over decades.
Should I adjust for inflation?
Yes, inflation erodes purchasing power. A 10% nominal return with 3% inflation gives ~7% real return. Use the inflation toggle to see your investment in today dollars.
How much should I invest monthly?
A common guideline is to invest 15-20% of gross income for retirement. Start with what you can afford and increase over time. Consistency matters more than amount.
Is this investment calculator free?
Yes, completely free with no sign-up. All calculations happen in your browser — your financial data is never sent to any server.