70/30 Portfolio Calculator
The 70/30 portfolio holds 70% stocks and 30% bonds, a growth-tilted step up from the classic 60/40 mix. 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
A 70/30 portfolio leans further into stocks than the 60/40 mix, trading some stability for more expected 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 compare against a more balanced split, use the 60/40 portfolio calculator or the asset allocation calculator.
A worked example
Say you invest $70,000 in stocks and $30,000 in bonds, for $100,000 total. That is a 70% stock, 30% bond split.
The calculator shows an expected return of 8.20% and volatility of 11.45%, giving a Sharpe ratio of 0.50. Held for 30 years with no extra contributions, that $100,000 grows to about $1,063,697 in the model — roughly $163,000 more than the same starting balance in a 60/40 mix, in exchange for higher volatility along the way.
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.
- Assuming the extra stock weight only adds upside. A 70/30 mix also carries more downside in a bad year than a 60/40 mix.
- Forgetting to rebalance. Strong stock markets can push a 70/30 mix past 80% stocks within a few years if you never trim back.
- Picking 70/30 for its higher expected return without checking the volatility figure — a bumpier ride you can't stomach can lead to panic-selling at the worst time.
- Ignoring your time horizon. A 70/30 split suits a longer runway; it can be too aggressive within a few years of a spending goal.
Frequently asked questions
What is a 70/30 portfolio?
A 70/30 portfolio holds 70% in stocks and 30% in bonds. It sits between the classic 60/40 mix and an all-stock portfolio, aiming for more growth than 60/40 while still holding a meaningful bond cushion.
What return does the 70/30 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 70/30 mix, that gives an expected return of 8.20% and volatility of 11.45%. These are long-run estimates, not promises.
Is 70/30 better than 60/40?
Not universally — it's a different risk tradeoff. In the model, 70/30 has a higher expected return (8.20% vs 7.60%) but also higher volatility (11.45% vs 10.00%). A younger investor with a long time horizon may prefer 70/30; someone closer to needing the money may prefer 60/40's smaller swings.
How much can a 70/30 portfolio grow over 30 years?
In the model, $100,000 split 70/30 with no added contributions grows to about $1,063,697 over 30 years, using an 8.20% expected return. Actual results will differ because real markets rise and fall.
How often should I rebalance a 70/30 portfolio?
Many investors rebalance once a year or when the mix drifts a set amount, such as 5 percentage points, from target. Without rebalancing, a strong stock run can quietly push a 70/30 portfolio toward 80/20 or higher, raising your risk beyond what you originally chose.
Sources
We prioritize primary sources for rules, formulas, rates, limits, and definitions. See our calculator methodology and editorial policy.