Required Return vs Realistic Return

A common financial planning error is building a plan around return assumptions that the market cannot deliver. Someone calculates: "I need $2M by age 60. I'm 40 now. I can save $1,000/month. To hit my goal, I need 9.5% annual returns." Then they invest conservatively in 60/40 bonds/stocks, which historically deliver 6–7% returns. They've built a plan that cannot win.

This article clarifies the gap between required returns (what the math demands) and realistic returns (what the market and your asset allocation can provide). It teaches the uncomfortable truth: if required returns exceed realistic returns, you cannot escape by choosing better stocks or market-timing. You must adjust the plan itself—save more, work longer, or lower the goal.

Key takeaways

• Required return is the annual return your investments must earn to hit your goal on schedule
• Realistic return is the long-term expected return of your chosen asset allocation, based on history
• If required exceeds realistic, your plan is not viable as stated
• The only solutions are: increase savings, extend timeline, or reduce goal
• Asset allocation should flow from your plan, not vice versa

Calculating required return: A reminder

In the previous article, we calculated: given a target, current balance, and timeline, what monthly contribution is needed? The inverse question is: given a fixed contribution, what return rate must you earn?

Example: You have $100,000 saved. You want $2M in 20 years. You can save $3,000/month. What annual return do you need?

Using Excel Goal Seek or a financial calculator:

Find the return rate that solves:
FV = 100,000 × (1.r)^20 + 3,000 × annual_factor
= 2,000,000

The answer is approximately 6.8% annually. Your required return is 6.8%.

Now, is 6.8% realistic?

Realistic returns: History and asset allocation

Long-term expected returns vary by asset class:

US equities (stocks)

• Historical nominal return: ~10% annually (1926–2023)
• Recent decades (2000–2023): ~8% annually
• Current expectations (2024): 6–7% annually, depending on valuations and analyst forecasts

International developed-market equities (VXUS, VWRL)

• Historical: ~7–9% annually
• Current expectations: 5–7% annually

Bonds (BND, aggregate)

• Historical: ~5–6% annually
• Current expectations (2024): 3–5% annually, due to higher yields
• Treasury yields at time of writing are 4–5%, so longer-term returns likely ~4–5%

Balanced 60/40 portfolio (60% stocks, 40% bonds)

• Historical: ~7–8% annually
• Current expectations: 5–6% annually

Conservative 40/60 or 50/50 portfolio

• Historical: ~5–6% annually
• Current expectations: 4–5% annually

Key point: current expectations are lower than historical returns, because bond yields are lower and stock valuations are higher relative to earnings (cyclically).

Scenarios: When math breaks down

Scenario A: Unrealistic plan

• Goal: $2M
• Current balance: $50,000
• Timeline: 20 years
• Savings: $1,500/month
• Required return: 8.1% annually

Can a typical investor achieve 8.1%? If they hold 70/30 stocks/bonds, they might average 7–7.5%. If they hold 80/20, they might average 7.5–8%. So yes, 8.1% is stretching but potentially doable if you're willing to endure 25–30% drawdowns in bear markets.

Scenario B: The math doesn't work

• Goal: $2.5M
• Current balance: $25,000
• Timeline: 20 years
• Savings: $2,000/month
• Required return: 9.8% annually

To achieve 9.8%, you'd need an aggressive 90/10 or 100% stocks portfolio. That's possible historically, but not guaranteed. More importantly, it requires you to hold 100% stocks for 20 years, enduring 40%+ drawdowns, without panic-selling. Many people psychologically cannot do this.

Moreover, if the market underperforms—earning 8% instead of 9.8%—your timeline extends or your goal fails. There's no margin for error.

Scenario C: The unsolvable plan

• Goal: $3M
• Current balance: $10,000
• Timeline: 15 years
• Savings: $3,000/month
• Required return: 12.2% annually

12.2% is higher than historical stock returns. No realistic asset allocation can deliver this consistently. This plan is broken. Possible fixes:

1. Increase savings to $4,500/month (if possible)
2. Extend timeline to 20 years
3. Lower goal to $2.2M
4. Accept a lower return target and delay retirement

The sooner you identify such a plan, the better. Realizing at age 55 that you've been saving for a goal that needed 12% returns and you earned 7% is too late.

The hard conversation: Trade-offs

When required return exceeds realistic return, you cannot solve it by stock-picking or market-timing. You must trade off three variables: timeline, contributions, or goal.

Option 1: Increase contributions If you can increase savings from $2,000 to $3,000/month, your required return drops. The math becomes feasible.

Drawback: You're already trying to save as much as possible. Income is constrained. This option feels impossible.

Option 2: Extend the timeline Instead of retiring at 60, retire at 62 or 65. Those extra years allow compound growth to do more work. Required returns fall dramatically.

Example: Move from a 20-year to a 25-year timeline. Required return often drops from 8.5% to 6.5%—suddenly achievable with a 60/40 portfolio.

Drawback: Delayed retirement means more years of work, wear-and-tear, and deferred freedom.

Option 3: Lower the goal If you need $2M but can only achieve $1.6M with realistic returns, lower your retirement spending. Spend $64,000/year instead of $80,000/year. Live modestly, travel less, or pursue geographic arbitrage (move to a lower-cost region).

Drawback: Retirement might be less comfortable than imagined.

Option 4: Hybrid adjustment Increase contributions by 10%, extend the timeline by 3 years, and lower the goal by 5%. Each small adjustment compounds.

Most successful financial plans involve all three: saving more (if possible), working a bit longer (to age 62–63 instead of 60), and accepting a moderate retirement lifestyle (not lavish).

Case study: The ambitious couple

David and Lisa are both 35. They earn $250,000 combined. Their goal is to retire at 50—15 years from now—on $120,000/year spending. They've saved $150,000 so far.

Their FI target: $120,000 × 25 = $3M.

They can save $4,000/month ($48,000/year). In 15 years, at 7% returns:

FV = 150,000 × (1.07)^15 + 4,000 × [((1.07)^15 - 1) / 0.07]
= 415,000 + 1,030,000
= $1,445,000

They'll accumulate only $1.445M, not $3M. They're short by $1.555M.

What return rate is needed?

Solve: 150,000 × (1.r)^15 + 4,000 × factor = 3,000,000
r ≈ 12.1% annually

12.1% is unrealistic. A 100% stock portfolio has never reliably delivered 12% annually for 15 years.

Their options:

1. Increase savings to $7,500/month (net income is tight; this requires cutting lifestyle significantly or increasing income).
2. Retire at 55 instead of 50 (25-year timeline, required return drops to 8.5%—much more realistic).
3. Retire on $2M, not $3M ($80,000/year spending, more modest).
4. Hybrid: increase savings to $5,000/month, extend to 18 years, reduce goal to $2.6M.

David and Lisa likely choose the hybrid: work until 53, save aggressively, live on $104,000/year in retirement (not $120,000), and retire with confidence. This plan is achievable.

Return assumptions and valuations

Current market valuations affect realistic return expectations. When the S&P 500 trades at 20× earnings (historical average), expected returns are reasonable. When it trades at 30× earnings (high valuation), expected returns are lower because future growth is priced in.

As of 2024, US equities are trading at elevated valuations, and bond yields are elevated. Expected returns from a 60/40 portfolio might be 5–6%, not the historical 7–8%. This means plans assuming 7–8% returns are more aggressive than they appear.

Monitoring valuations—using metrics like Shiller PE ratio or dividend yield—helps keep return assumptions grounded in reality, not wishful thinking.

Asset allocation as a servant, not a master

A common mistake is choosing asset allocation first ("I want to buy growth stocks"), then calculating returns. Reverse the logic.

First, calculate your required return. Then choose an asset allocation that can deliver it. If your required return is 6.5%, a 50/50 stock/bond portfolio is appropriate. If it's 8%, you need 75/25 or 80/20. If it's 12%, no allocation works—go back and adjust your plan.

Asset allocation should flow from your plan, not drive it. Too many investors pick an allocation (50/50 seems safe) and then hope it's enough. Better to know your required return, match an allocation to it, and stress-test against realistic scenarios.

The emotional payoff of honest math

Accepting that you need to work until 63 instead of 60 is uncomfortable. Accepting that retirement spending will be $90,000, not $120,000, is disappointing. But accepting reality early—at 35, when you have time to adjust—is far better than discovering at 58 that your plan cannot work.

Honest math forces uncomfortable conversations with yourself and your partner. But it prevents the much larger disappointment of underfunded retirement.

Decision tree

Related concepts

• Time-to-Goal Calculations
• Financial Independence Goal
• Writing the Investment Policy Statement

Next

Once you've resolved the required-vs-realistic return gap and your plan is mathematically sound, the next step is formalizing your goals using the SMART framework—turning vague intentions into specific, measurable commitments with timelines.