Retirement savings by age 40: Benchmarks, trajectory models, and catch-up strategies

Fidelity's recommendation to have 3× your annual salary saved by age 40 is derived from Monte Carlo simulations targeting a 90% probability of maintaining pre-retirement income levels through age 95 — assuming Social Security benefits, a 15% savings rate from age 25 onward, and a 5.5% blended real return.

This benchmark breaks down for two large cohorts: workers who started saving late, and high-income earners who receive proportionally less from Social Security.

For a complete household financial framework, see our household capital allocation and debt framework.

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Income-adjusted retirement benchmarks at age 40

The 3× multiplier is calibrated for median earners. Social Security replaces a larger proportion of income for lower earners (up to 90% of the first $1,115/month in 2026) and a smaller proportion for high earners:

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The Trinity Study and safe withdrawal rates

The Trinity Study (Cooley, Hubbard, Walz, 1998; updated 2011 and 2022) established the 4% safe withdrawal rate (SWR) as the percentage of initial portfolio value that can be withdrawn annually with 95% probability of portfolio survival through 30 years of retirement.

$$\text{Nest Egg Required} = \frac{\text{Annual Retirement Spending - Annual SS Benefit}}{\text{SWR}}$$

For a household spending $120,000/year in retirement with $36,000 in Social Security benefits (combined), needing $84,000 from portfolio:

$$\text{Nest Egg} = \frac{$84,000}{4.0%} = $2,100,000$$

Updated SWR research (Pfau, Kitces, Finke — 2020–2024): In today's lower-yield environment, a more conservative 3.5% SWR is recommended for 40-year retirement horizons, requiring 28.6× annual portfolio income needs.

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Catch-up modeling for age 40 deficits

Scenario: $100K salary, $150K saved at 40 (deficit vs $300K Fidelity target)

Annual catch-up calculation using future value equation:

$$FV = PV \times (1 + r)^n + PMT \times \frac{(1 + r)^n - 1}{r}$$

At current trajectory (15% savings rate, 7% return):

• $150K × (1.07)^{25} = $814K
• $15K/yr × [(1.07)^{25} - 1] / 0.07 = $949K
• Projected balance at 65: $1,763K

With additional 5% catch-up (20% savings rate):

• $150K × (1.07)^{25} = $814K
• $20K/yr × [(1.07)^{25} - 1] / 0.07 = $1,266K
• Projected balance at 65: $2,080K

A 5% increase in savings rate from 40–65 recovers the $150K deficit entirely through compounding, generating $317K in additional wealth.

Use the Retirement Readiness Benchmark to compare your current savings trajectory against income-adjusted benchmarks and model the savings rate increase required to reach your specific retirement income target.