90/10 Portfolio Calculator
The 90/10 portfolio holds 90% stocks and 10% bonds. It's the most stock-heavy fixed mix on this site and is built for investors with a very 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 what the numbers look like for your money.
These figures are long-run model estimates, not guarantees.
How it's calculated
A 90/10 portfolio keeps only a thin bond slice, leaning almost entirely on stocks for growth. 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 $90,000 in stocks and $10,000 in bonds, for $100,000 total. That is a 90% stock, 10% bond split.
The calculator shows an expected return of 9.40% and volatility of 14.46%, giving a Sharpe ratio of 0.48. Held for 30 years with no extra contributions, that $100,000 grows to about $1,480,879 in the model — the highest projected balance of any fixed mix on this site, and also the widest one-year range.
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 90/10 with a short time horizon. A 10% bond cushion barely dampens a stock selloff, so this mix needs years to recover from a bad stretch.
- Skipping the volatility check. A 90/10 mix carries the highest swing of any fixed split on this site, and the extra expected return over 80/20 is small.
- Never rebalancing. With only a 10% bond weight to start, a strong bull market can push a 90/10 mix to nearly all stocks within a few years.
- Assuming more stock weight always pays off. The Sharpe ratio — return per unit of risk — can actually be lower at 90/10 than at a less extreme mix; check both numbers, not just the expected return.
Frequently asked questions
What is a 90/10 portfolio?
A 90/10 portfolio holds 90% in stocks and 10% in bonds. It's the most aggressive fixed mix on this site, keeping only a thin bond cushion, and it typically suits investors with a very long time horizon and a high tolerance for swings.
What return does the 90/10 portfolio calculator assume?
The calculator models stocks at a 10% return with 16% volatility and bonds at a 4% return with 5% volatility. For a 90/10 mix, that gives an expected return of 9.40% and volatility of 14.46%. These are long-run estimates, not promises.
Is 90/10 too aggressive?
It depends on your time horizon and how you'd react to a large drawdown. In the model, 90/10 carries 14.46% volatility, the highest of any fixed mix on this site, for a Sharpe ratio of 0.48 — slightly below 80/20's 0.49. For a saver decades from needing the money, the extra risk is often an acceptable tradeoff; for most others, a less extreme mix delivers nearly the same growth with a smoother ride.
How much can a 90/10 portfolio grow over 30 years?
In the model, $100,000 split 90/10 with no added contributions grows to about $1,480,879 over 30 years, using a 9.40% expected return. Actual results will differ because real markets rise and fall, sometimes sharply.
90/10 vs 60/40 portfolio: what's the tradeoff?
In the model, 90/10 has a meaningfully higher expected return (9.40% vs 7.60%) and higher volatility (14.46% vs 10.00%) than 60/40. Over 30 years with no added contributions, $100,000 grows to about $1,480,879 in a 90/10 mix versus about $900,260 in a 60/40 mix — roughly $580,000 more, in exchange for a much wider range of possible one-year outcomes. Run your own numbers in the 60/40 portfolio calculator.
90/10 vs 80/20 portfolio: is the extra stock weight worth it?
In the model, 90/10 edges out 80/20 on raw expected return (9.40% vs 8.80%) but actually has a slightly lower Sharpe ratio (0.48 vs 0.49), meaning 80/20 delivers marginally more return per unit of risk taken. See the full 80/20 vs 90/10 portfolio comparison for the complete numbers, including the 30-year growth gap and the worst-case 1-year range for each.
Sources
We prioritize primary sources for rules, formulas, rates, limits, and definitions. See our calculator methodology and editorial policy.