Investment Return Calculator
Use this investment return calculator to project how your money can grow over time with compound interest. Enter your initial investment, monthly contributions, interest rate, and time horizon to see future value estimates. Perfect for long-term financial planning, retirement savings, and wealth building strategies.
Investment Details
Growth Projection
Enter your investment details to see your growth projection.
How Compound Growth Works
Compound growth means earning returns on your returns. With a $10,000 investment at 8% annually: Year 1 earns $800 (total: $10,800). Year 2 earns $864 (8% of $10,800, total: $11,664). Year 3 earns $933 (total: $12,597). Each year's return is larger than the last because it applies to a growing base. Over 30 years at 8%, that $10,000 becomes about $100,627 — ten times the original investment without adding another dollar.
Compounding frequency matters too: daily compounding grows faster than annual compounding at the same stated rate. A 8% rate compounded daily produces an effective annual yield of 8.33%, versus exactly 8% for annual compounding. For most long-term investments like index funds, annual compounding is the standard assumption in projections.
Realistic Return Expectations
The US stock market (S&P 500) has averaged about 10% annually before inflation since 1926, and about 7% after inflation. Diversified bond portfolios return roughly 4–5% annually. A balanced 60/40 stock/bond portfolio has historically averaged 7–8% before inflation. These long-run averages smooth out decades of volatility — the actual year-to-year returns ranged from −38% (2008) to +38% (1995) for the S&P 500. When using this calculator, use conservative rates (5–7%) for 10–20 year projections, and recognize that actual returns will differ from any projection.
Frequently Asked Questions
What is a realistic annual return for a retirement portfolio?
Financial planners commonly use 5–7% as a long-run real return assumption (after inflation) for diversified equity-heavy portfolios. Nominal (before inflation) assumptions are typically 7–9% for a stock-heavy portfolio and 4–6% for a balanced portfolio. More conservative plans use 5–6% nominal to build in a margin of safety. The exact figure depends on your asset allocation — more stocks historically means higher returns and higher volatility; more bonds means lower but more stable returns. For projections more than 20 years out, the assumed rate has an enormous impact on the final number, so running scenarios at multiple rates (5%, 7%, 9%) is more informative than a single projection.
What's the difference between nominal and real (inflation-adjusted) returns?
Nominal return is the actual percentage gain. Real return adjusts for inflation — what the money actually buys. If your investment grows 8% in a year when inflation is 3%, your real return is approximately 5% (more precisely: 1.08 ÷ 1.03 − 1 = 4.85%). Real returns matter because future dollars buy less than today's dollars. A projection showing $1 million in 30 years sounds impressive — but at 3% inflation, that $1 million has the purchasing power of about $412,000 in today's dollars. When planning for retirement or future expenses, always check whether projections are in nominal or inflation-adjusted terms.
How much does starting to invest early really matter?
Enormously. A $10,000 investment at age 25 growing at 7% annually reaches about $149,745 by age 65. The same $10,000 invested at age 35 reaches only $76,123 — half as much, despite only 10 fewer years. The last decade of compounding (ages 55–65) adds more dollar value than the entire first 30 years combined. This is why time in the market is consistently emphasized over timing the market: missing the best growth years at the end of a long compound period is far more costly than a temporary downturn or a delayed start, because compounding's power grows exponentially over time.