Investment Compounding Calculator

Inputs

Current age Target ages (comma separated)

Monthly contribution

$

Initial lump sum at start

$

Asset / scenario Selecting an asset fills the expected annual return using a long term nominal scenario, not a forecast. Risk profile preset Risk presets adjust asset and return assumptions in one click. Expected annual return (percent, before inflation and tax) BTC presets are based on past performance and are for illustration only, not predictions or advice. Approx tax on gains (percent) This applies a simple tax drag approximation on returns. For tax-sheltered accounts, leave at 0 percent. Inflation assumption (percent per year) Real returns ≈ (1 + nominal) / (1 + inflation) − 1. This keeps long term projections realistic. Annual increase in contribution (percent) Start year (optional)

Custom portfolio mix (optional)

Build a simple three-position portfolio. If the symbol matches a preset (SPY, QQQ, IWM, VT, VTI, VXUS, XLY, XLK, XLF, XLE, BTC, ETH), the tool will use its nominal long term return to compute a weighted average.

Symbol Weight (percent)

Retirement / withdrawal phase (optional)

Enable retirement withdrawals Retirement age Withdrawal rate per year (percent of portfolio) Years in retirement

In retirement, contributions stop at the chosen age and the tool simulates an annual withdrawal while the portfolio continues to grow.

What is CAGR?

CAGR stands for Compound Annual Growth Rate. It represents the average yearly return of an investment as if it grew at a steady rate every year, with profits reinvested, even if actual year to year performance is very volatile.

In other words, it answers the question: "What constant yearly percentage return would turn my starting amount into my ending amount over this period?"

CAGR = (Ending value / Starting value) ^ (1 / Years) − 1

Example: if 1 000 dollars becomes 2 000 dollars in 5 years, the CAGR is about 14.9 percent per year. Asset presets on this page are simplified long term scenarios for education only – not promises or advice.

Year by year breakdown

Age	Year	Total invested	Portfolio value	Profit	Withdrawn
No data yet.

Understanding these projections

Nominal vs real returns

Nominal returns ignore inflation. Real returns subtract the effect of rising prices. For long horizons, a portfolio growing at 7 percent with 3 percent inflation is only compounding at roughly 4 percent in terms of purchasing power. Using real returns helps you think in "today's dollars".

What return should I use?

Very roughly: global stock indexes often use 6–8 percent nominal, balanced stock/bond mixes 4–6 percent, and cash-like assets 1–3 percent. Crypto assets like Bitcoin had explosive historical growth, but forward-looking assumptions above 20–30 percent per year quickly lead to unrealistic long term numbers.

How much should I invest monthly?

A common rule of thumb is to invest 10–20 percent of your income across retirement and long term goals. This tool lets you see the trade-off between starting small and increasing over time versus committing to a higher amount from the beginning.

FAQ (short version)

These are projections, not guarantees.
Markets are volatile and do not move in straight lines.
Inflation, taxes and fees can dramatically change real outcomes.
Crypto scenarios are especially uncertain and should be treated as experiments, not promises.

Risk and disclaimer

This page is for education only and does not provide financial advice, recommendations, or individualized planning. Past performance does not guarantee future results. Always consider your own risk tolerance, time horizon, and legal/tax situation before making investment decisions.