What This Calculator Does
The Microapp Stock Return Calculator projects a stock or ETF portfolio from today to your target year. Unlike a generic compound-interest tool, it separates the return into two pieces — price appreciation and dividend yield — the way real index data is reported. You decide whether to reinvest dividends or take them as cash, optionally deflate the final number into today's dollars for an inflation-adjusted answer, and read the result along with a year-by-year balance you can sanity-check against your own brokerage statements.
Total contributions: $130,000
Final nominal value: ~$413,000
Total gains: ~$283,000
Money-weighted CAGR: ~6.0%
In today's dollars (after 3% inflation): ~$229,000
Real CAGR: ~2.9%
The nominal number sounds enormous; the real number is what your future self can actually buy with it.
Why Split Price Appreciation From Dividend Yield?
Because real index data is reported that way, and because the split matters when dividends aren't reinvested. The S&P 500's roughly 10% long-term total return is usually broken down as ~6-7% price appreciation + ~1.5-2% dividend yield. A dividend-focused ETF like SCHD might split closer to 4% price + 3.5% dividend. A high-yield individual stock might split 2% price + 6% dividend. Total return is similar across these, but the cash-flow profile is very different — and if you're spending the dividends, only the price half compounds.
The other reason: when you're inputting expectations rather than measuring history, you may have different conviction in the two pieces. You can be reasonably confident that S&P dividends will stay around 1.5-2% — corporate boards are conservative about dividend cuts. You're much less confident about price appreciation, which has run anywhere from −1% to +13% real, depending on the 30-year window you pick. Splitting the inputs lets you stress-test each piece independently.
Dividend Reinvestment — the Compounding That Most People Skip
If you don't need the income now, reinvest your dividends. Over long windows it's the single biggest difference between average returns and the headline 10% figure quoted for the S&P 500.
| Scenario (S&P 500, 30 years, $10k initial, $500/mo) | Final value |
|---|---|
| Price appreciation only (6% return, no dividends) | ~$546,000 |
| 6% price + 2% dividend, NOT reinvested (cash on the side) | ~$617,000 (portfolio: $546k + accumulated dividends: $71k cash) |
| 6% price + 2% dividend, REINVESTED (compounds back in) | ~$777,000 |
Reinvesting beats taking dividends as cash by about $160,000 over 30 years in this scenario, even though the same dollars of dividends are paid in both cases. The difference is that reinvested dividends buy more shares, which generate more dividends, which buy more shares — compounding within compounding.
The case for taking dividends as cash is narrow: you're already retired and using the cash to live on, or you want to redirect them into a tax-advantaged account or different asset class. Otherwise, enable DRIP (Dividend ReInvestment Plan — most brokers offer it free) once and forget about it.
Why Money-Weighted CAGR, Not Simple Lump-Sum CAGR
If you put $10,000 in and watched it grow to $20,000 over 10 years, the math is easy: CAGR = (20000/10000)^(1/10) − 1 = 7.18%/year. But real portfolios have monthly contributions, which means most of the money hasn't been invested for the full period. A dollar contributed in year 9 only compounds for one year before you check the balance.
Money-weighted CAGR fixes this by computing the per-dollar growth rate across the actual cash flow:
CAGR = (finalValue / totalContributions)^(1/years) − 1
It's the same formula as the simple CAGR, but the denominator is the sum of all contributions (initial + every monthly) rather than just the initial. The result is an honest number — what your portfolio actually earned per invested dollar — that won't flatter you the way a simple lump-sum calculation would. If you entered 8% as your expected return and the money-weighted CAGR comes out around 6%, that's not a bug — it's the calculator telling you that contributions arriving late in the period don't compound as long, so per-dollar growth across the whole pool is lower than the per-year compound rate.
Inflation — the Number That Makes the Projection Real
A $1M projection sounds great until you realize $1M in 30 years has the purchasing power of about $415,000 today (at 3% inflation). For any projection more than 5 years out, deflate the final value into today's dollars or the ending number doesn't mean anything you can plan around.
The math: real value = nominal value / (1 + inflation)^years. The calculator does this automatically when you fill in the inflation field — and computes a real CAGR alongside the nominal one. A real CAGR of 4-5% on a stock portfolio is excellent; 7%+ real is historically rare.
Recent US inflation: 2010-2019 averaged ~1.8%, 2020-2024 averaged ~4.0% (the 2022 peak hit 9%). Long-term average since 1913: ~3.2%. For conservative planning, use 3% — it's been close enough most of the time and slightly overstating inflation is safer than understating it.
What This Calculator Doesn't Capture
Sequence-of-returns risk. Real markets don't return a constant 8% — they swing from +30% years to −37% years. The constant-return projection gives you the right ENDING value on average but understates year-to-year variance. Near the start of accumulation this doesn't matter much (you have time to recover). Within 5-10 years of needing the money it matters a lot — a bad market year right before retirement can devastate a balance whose long-term average is fine. For sophisticated planning, look up Monte Carlo simulators.
Taxes. The projection is pre-tax. In a taxable brokerage, dividends are taxed annually (qualified dividends at 0/15/20%, ordinary at your marginal rate); capital gains are taxed at sale. In a Roth IRA/401(k) there are no taxes ever (after 59½). In a Traditional IRA/401(k) all withdrawals are taxed as ordinary income. The same nominal portfolio in different account types produces very different after-tax outcomes.
Fees. ETF expense ratios run 0.03-0.10% for broad-market index funds and 0.40%+ for actively-managed funds. Subtract your blended expense ratio from the return input to model fees. Over 30 years a 1% fee difference compounds to a ~25% lower ending balance.
Contribution growth. The calculator uses constant monthly contributions. In reality most people increase contributions over time as income rises. Real outcomes are usually better than the constant-rate projection.
Currency. If you hold international stocks, currency movements add another layer of return (and risk). The calculator implicitly assumes a single currency throughout.
Common Mistakes
Using 10% as the return without separating dividends. If you enter 10% in the price-appreciation field and add 2% dividend yield, you're double-counting. Use ~7% price + ~2% dividend (which totals to ~9% — close to the headline 10% S&P number but more realistic for forward returns).
Ignoring the inflation field. A nominal projection without an inflation adjustment is hard to interpret. $5M in 40 years sounds incredible until you realize it's about $1.5M in today's dollars at 3% inflation — still great, but not the same number.
Projecting individual stocks at "average market return." The S&P 500's 10% return is an INDEX return, smoothed across 500 companies. Most individual stocks underperform the index over long windows. If you're projecting a single stock, use a much lower expected return or admit you're speculating, not investing.
Anchoring on the exact number. The output is a point estimate from a smooth-return model. Real outcomes will be higher or lower depending on the actual sequence of market years. Treat the result as a midpoint, not a prediction.
Educational Tool — Not Investment Advice
This calculator implements the standard monthly-compounding future-value math with separated price/dividend returns. It's intended for projecting and stress-testing scenarios, not as a substitute for personalized financial advice. For specific decisions about asset allocation, account selection (Roth vs Traditional, IRA vs 401(k) vs taxable), tax-loss harvesting, or retirement-age planning, consult a fee-only fiduciary financial advisor.
Related Tools
Use the Compound Interest Calculator for a simpler single-rate projection without the dividend split — appropriate for savings accounts, CDs, and bonds. The 401(k) Calculator projects retirement balances with employer match included. The Savings Calculator handles low-rate cash-equivalent accounts.