80/20 Portfolio Calculator
The 80/20 portfolio holds 80% stocks and 20% bonds, an aggressive mix built for investors with a long time horizon. The calculator above shows its expected return, its risk, and how it might grow over time.
Enter your own stock and bond amounts to see the numbers for your money. These figures are long-run model estimates, not guarantees.
How it's calculated
An 80/20 portfolio leans heavily into stocks, keeping only a small bond cushion. The calculator above weights each asset by its share of your money. Stocks are modeled at a 10% return with 16% volatility. Bonds are modeled at a 4% return with 5% volatility.
The tool combines these into your portfolio's expected return, its volatility, and its Sharpe ratio, which measures return earned above a 2.5% risk-free rate per unit of risk. The growth projection compounds your expected return over the years you choose. To see a more balanced split, try the 60/40 portfolio calculator or the asset allocation calculator.
A worked example
Say you invest $80,000 in stocks and $20,000 in bonds, for $100,000 total. That is an 80% stock, 20% bond split.
The calculator shows an expected return of 8.80% and volatility of 12.94%, giving a Sharpe ratio of 0.49. Held for 30 years with no extra contributions, that $100,000 grows to about $1,255,645 in the model — the highest of the three fixed mixes on this site, and also the bumpiest ride.
Common mistakes to avoid
- Treating the 10% stock and 4% bond figures as guaranteed. They are long-run model assumptions, and real returns vary widely year to year.
- Holding 80/20 with a short time horizon. The higher stock weight needs years to recover from a bad stretch, so it fits a longer runway better than a near-term goal.
- Skipping the volatility check. An 80/20 mix carries meaningfully more swing than 60/40, and the higher expected return only shows up over the long run.
- Never rebalancing. A strong bull market can push an 80/20 mix toward 90% stocks or higher within a few years, well past what most investors intend.
- Confusing lower bond weight with no downside protection. The 20% bond slice still cushions some of the drop in a stock selloff, just less than a 60/40 or 70/30 mix would.
Frequently asked questions
What is an 80/20 portfolio?
An 80/20 portfolio holds 80% in stocks and 20% in bonds. It's an aggressive, growth-focused mix that keeps a small bond cushion rather than going fully into stocks, and it typically suits investors with a long time horizon and a higher tolerance for swings.
What return does the 80/20 portfolio calculator assume?
The calculator models stocks at a 10% return with 16% volatility and bonds at a 4% return with 5% volatility. For an 80/20 mix, that gives an expected return of 8.80% and volatility of 12.94%. These are long-run estimates, not promises.
Is 80/20 too aggressive?
It depends on your time horizon and how you'd react to a large drawdown. In the model, 80/20 carries 12.94% volatility, well above the 60/40 mix's 10.00%. For a saver decades from needing the money, that volatility is often an acceptable tradeoff for higher expected growth; for someone near a spending goal, it usually is not.
How much can an 80/20 portfolio grow over 30 years?
In the model, $100,000 split 80/20 with no added contributions grows to about $1,255,645 over 30 years, using an 8.80% expected return. Actual results will differ because real markets rise and fall, sometimes sharply.
80/20 vs 60/40 portfolio: what's the real tradeoff?
In the model, 80/20 has a higher expected return (8.80% vs 7.60%) and higher volatility (12.94% vs 10.00%) than 60/40. The 60/40 mix trades some growth for a smoother ride; 80/20 accepts bigger swings for a higher long-run projection. Neither is universally better — it depends on your time horizon and risk tolerance.
Sources
We prioritize primary sources for rules, formulas, rates, limits, and definitions. See our calculator methodology and editorial policy.